diff --git a/src/Contract/ContractParser.php b/src/Contract/ContractParser.php
index b8bde46..88bf37a 100644
--- a/src/Contract/ContractParser.php
+++ b/src/Contract/ContractParser.php
@@ -154,7 +154,11 @@ public static function parseProperty(string $className, string $propertyName): ?
             }
 
             $typeNode = $varTags[0]->type;
+
             $aliases = [];
+            $templates = [];
+            self::parseClassLevelDocs($declaringClass, $templates, $aliases);
+
             DocblockExtractor::extractAliases($phpDocNode, $aliases, $declaringClass);
 
             $typeNode = self::substituteAliases($typeNode, $aliases);
@@ -180,14 +184,9 @@ public static function parseClassAliases(string $className): array
         try {
             /** @var class-string<object> $className */
             $refClass = new \ReflectionClass($className);
-            $doc = $refClass->getDocComment();
-            if ($doc === false) {
-                return [];
-            }
-
-            $phpDocNode = DocblockExtractor::parseDocString($doc);
             $aliases = [];
-            DocblockExtractor::extractAliases($phpDocNode, $aliases, $refClass);
+            $templates = [];
+            self::parseClassLevelDocs($refClass, $templates, $aliases);
 
             return $aliases;
         } catch (\Throwable $e) {
@@ -462,7 +461,7 @@ private static function substituteAliases(TypeNode $node, array $aliases): TypeN
         if ($node instanceof GenericTypeNode) {
             $genericType = self::substituteAliases($node->type, $aliases);
             $genericTypes = array_map(
-                fn ($t) => self::substituteAliases($t, $aliases),
+                fn($t) => self::substituteAliases($t, $aliases),
                 $node->genericTypes
             );
 
@@ -479,14 +478,14 @@ private static function substituteAliases(TypeNode $node, array $aliases): TypeN
 
         if ($node instanceof UnionTypeNode) {
             return new UnionTypeNode(array_map(
-                fn ($t) => self::substituteAliases($t, $aliases),
+                fn($t) => self::substituteAliases($t, $aliases),
                 $node->types
             ));
         }
 
         if ($node instanceof IntersectionTypeNode) {
             return new IntersectionTypeNode(array_map(
-                fn ($t) => self::substituteAliases($t, $aliases),
+                fn($t) => self::substituteAliases($t, $aliases),
                 $node->types
             ));
         }
diff --git a/src/Contract/DocblockExtractor.php b/src/Contract/DocblockExtractor.php
index 31b5d41..b54f973 100644
--- a/src/Contract/DocblockExtractor.php
+++ b/src/Contract/DocblockExtractor.php
@@ -114,15 +114,19 @@ public static function extractAliases(
         \ReflectionClass|\ReflectionFunction|\ReflectionMethod $ref
     ): void {
         foreach ($phpDocNode->getTypeAliasTagValues() as $aliasTag) {
-            $aliases[$aliasTag->alias] = $aliasTag->type;
+            if (!isset($aliases[$aliasTag->alias])) {
+                $aliases[$aliasTag->alias] = $aliasTag->type;
+            }
         }
 
         foreach ($phpDocNode->getTypeAliasImportTagValues() as $importTag) {
             $localName = $importTag->importedAs ?? $importTag->importedAlias;
-            $fqcnSource = SpecialTypeResolver::resolveFqcn($importTag->importedFrom->name, $ref);
-            $resolvedType = self::resolveImportedTypeAlias($fqcnSource, $importTag->importedAlias);
-            if ($resolvedType !== null) {
-                $aliases[$localName] = $resolvedType;
+            if (!isset($aliases[$localName])) {
+                $fqcnSource = SpecialTypeResolver::resolveFqcn($importTag->importedFrom->name, $ref);
+                $resolvedType = self::resolveImportedTypeAlias($fqcnSource, $importTag->importedAlias);
+                if ($resolvedType !== null) {
+                    $aliases[$localName] = $resolvedType;
+                }
             }
         }
     }
diff --git a/src/Validator/UnionValidator.php b/src/Validator/UnionValidator.php
index 101cbbc..59af4d1 100644
--- a/src/Validator/UnionValidator.php
+++ b/src/Validator/UnionValidator.php
@@ -20,12 +20,34 @@ public function validate(mixed $value, TypeNode $node, string $context, TypeVali
         /** @var UnionTypeNode $unionNode */
         $unionNode = $node;
 
+        $deepErrors = [];
+
         foreach ($unionNode->types as $type) {
-            if ($registry->validate($value, $type, $context) === null) {
+            $err = $registry->validate($value, $type, $context);
+            if ($err === null) {
                 return null;
             }
+
+            $msg = $err->getMessage();
+            
+            if (
+                str_starts_with($msg, $context . '[') ||
+                str_starts_with($msg, $context . '->') ||
+                str_starts_with($msg, $context . ' is missing required') ||
+                str_starts_with($msg, $context . ' contains unsealed') ||
+                str_starts_with($msg, $context . ' property') ||
+                str_starts_with($msg, $context . ' key') ||
+                str_starts_with($msg, $context . ' value') ||
+                str_starts_with($msg, $context . ' extra key')
+            ) {
+                $deepErrors[] = $err;
+            }
+        }
+
+        if (\count($deepErrors) > 0) {
+            return $deepErrors[0];
         }
 
         return ErrorFactory::createError($context . ' must be of type ' . $unionNode . ', ' . TypeFormatter::formatGivenValue($value) . ' given');
     }
-}
+}
\ No newline at end of file
diff --git a/tests/Fixtures/Types/Imported/ClassUsingTraitWithAlias.php b/tests/Fixtures/Types/Imported/ClassUsingTraitWithAlias.php
new file mode 100644
index 0000000..076360b
--- /dev/null
+++ b/tests/Fixtures/Types/Imported/ClassUsingTraitWithAlias.php
@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TypePHP\Tests\Fixtures\Types\Imported;
+
+class ClassUsingTraitWithAlias
+{
+    use TraitWithAlias;
+}
\ No newline at end of file
diff --git a/tests/Fixtures/Types/Imported/DbalKernelPluginLoader.php b/tests/Fixtures/Types/Imported/DbalKernelPluginLoader.php
new file mode 100644
index 0000000..7a72fb4
--- /dev/null
+++ b/tests/Fixtures/Types/Imported/DbalKernelPluginLoader.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TypePHP\Tests\Fixtures\Types\Imported;
+
+/**
+ * @phpstan-import-type PluginInfo from KernelPluginLoader
+ * @phpstan-type SharedConfig array{retries: positive-int, strict: bool}
+ */
+class DbalKernelPluginLoader extends KernelPluginLoader
+{
+    /** 
+     * Tests child overriding a parent's type alias 
+     * (SharedConfig in parent was just array{retries: int})
+     * 
+     * @var SharedConfig 
+     */
+    public array $config = ['retries' => 3, 'strict' => true];
+
+    public function load(): void
+    {
+        $this->pluginInfos = [
+            ['name' => 'SwagPayPal', 'active' => true],
+        ];
+    }
+
+    public function loadBad(): void
+    {
+        $this->pluginInfos = [
+            ['name' => 'SwagPayPal', 'active' => 'yes'],
+        ];
+    }
+}
\ No newline at end of file
diff --git a/tests/Fixtures/Types/Imported/KernelPluginLoader.php b/tests/Fixtures/Types/Imported/KernelPluginLoader.php
new file mode 100644
index 0000000..8906059
--- /dev/null
+++ b/tests/Fixtures/Types/Imported/KernelPluginLoader.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TypePHP\Tests\Fixtures\Types\Imported;
+
+/**
+ * @phpstan-type PluginInfo array{name: string, active: bool}
+ * @phpstan-type SharedConfig array{retries: int}
+ */
+abstract class KernelPluginLoader
+{
+    /** @var list<PluginInfo> */
+    public array $pluginInfos = [];
+}
\ No newline at end of file
diff --git a/tests/Fixtures/Types/Imported/TraitWithAlias.php b/tests/Fixtures/Types/Imported/TraitWithAlias.php
new file mode 100644
index 0000000..80c8a83
--- /dev/null
+++ b/tests/Fixtures/Types/Imported/TraitWithAlias.php
@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TypePHP\Tests\Fixtures\Types\Imported;
+
+/**
+ * @phpstan-type TraitShape array{x: int, y: int}
+ */
+trait TraitWithAlias
+{
+    /** @var TraitShape */
+    public array $coordinates = ['x' => 0, 'y' => 0];
+}
\ No newline at end of file
diff --git a/tests/TypeChecking/ArraysAndShapes/ImportedTypePropertyTest.php b/tests/TypeChecking/ArraysAndShapes/ImportedTypePropertyTest.php
new file mode 100644
index 0000000..e748c21
--- /dev/null
+++ b/tests/TypeChecking/ArraysAndShapes/ImportedTypePropertyTest.php
@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+use TypePHP\Tests\Fixtures\Types\Imported\DbalKernelPluginLoader;
+use TypePHP\Tests\Fixtures\Types\Imported\ClassUsingTraitWithAlias;
+
+describe('Class-Level Imported Types on Properties', function () {
+    
+    test('resolves @phpstan-type and @phpstan-import-type on class properties', function () {
+        $loader = new DbalKernelPluginLoader();
+        $loader->load();
+        
+        expect($loader->pluginInfos)->toHaveCount(1);
+        expect($loader->pluginInfos[0]['name'])->toBe('SwagPayPal');
+    });
+    
+    test('fails correctly when the imported array shape is actually violated', function () {
+        $loader = new DbalKernelPluginLoader();
+        
+        expect(fn() => $loader->loadBad())
+            ->toThrow(\TypeError::class, "['active']");
+    });
+
+    test('resolves overridden aliases in child class without breaking parent inheritance', function () {
+        $loader = new DbalKernelPluginLoader();
+        
+        $loader->config = ['retries' => 5, 'strict' => false];
+        expect($loader->config)->toBe(['retries' => 5, 'strict' => false]);
+        
+        expect(fn() => $loader->config = ['retries' => -1, 'strict' => false])
+            ->toThrow(\TypeError::class, "['retries'] must be of type positive-int");
+    });
+
+    test('resolves aliases defined on traits applied to properties inside the trait', function () {
+        $instance = new ClassUsingTraitWithAlias();
+
+        expect($instance->coordinates)->toBe(['x' => 0, 'y' => 0]);
+
+        $instance->coordinates = ['x' => 10, 'y' => 20];
+        expect($instance->coordinates['x'])->toBe(10);
+
+        expect(fn() => $instance->coordinates = ['x' => 10, 'y' => 'invalid'])
+            ->toThrow(\TypeError::class, "['y'] must be of type int");
+    });
+});
\ No newline at end of file
diff --git a/tests/TypeChecking/ArraysAndShapes/UnionErrorBubblingTest.php b/tests/TypeChecking/ArraysAndShapes/UnionErrorBubblingTest.php
new file mode 100644
index 0000000..5454634
--- /dev/null
+++ b/tests/TypeChecking/ArraysAndShapes/UnionErrorBubblingTest.php
@@ -0,0 +1,135 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @param array{id: int, tags: list<string|int>}|null $payload
+ */
+function testDeepUnionError(mixed $payload): bool
+{
+    return true;
+}
+
+/**
+ * @return array{name: string, args: list<string|int|false>}|null
+ */
+function testAttributeCompilerSim(): ?array
+{
+    return [
+        'name' => 'Field',
+        'args' => ['column', 'property', new \stdClass()],
+    ];
+}
+
+/**
+ * @param object{id: positive-int, profile: object{name: non-empty-string}}|null $user
+ */
+function testDeepObjectShapeUnion(mixed $user): bool
+{
+    return true;
+}
+
+/**
+ * @param object{id: int, role: string}|null $data
+ */
+function testMissingObjectPropertyUnion(mixed $data): bool
+{
+    return true;
+}
+
+/**
+ * @param object{name: string}|null $data
+ */
+function testUninitializedObjectPropertyUnion(mixed $data): bool
+{
+    return true;
+}
+
+/**
+ * @param (array{type: 'A', data: array{score: positive-int}} | array{type: 'B', data: array{code: non-empty-string}})|null $discriminated
+ */
+function testDiscriminatedUnionDeepError(mixed $discriminated): bool
+{
+    return true;
+}
+
+class PropertyUnionFixture
+{
+    /**
+     * @var array{config: array{enabled: bool}}|null
+     */
+    public ?array $settings = null;
+}
+
+describe('Union Deep Error Bubbling', function () {
+    test('surfaces deep array shape error instead of generic union error', function () {
+        expect(fn() => testDeepUnionError(['id' => 10, 'tags' => ['hello', false]]))
+            ->toThrow(\TypeError::class, "Argument \$payload['tags'][1] must be of type (string | int)");
+    });
+
+    test('surfaces deep return shape error mimicking AttributeEntityCompiler', function () {
+        expect(fn() => testAttributeCompilerSim())
+            ->toThrow(\TypeError::class, "Return value['args'][2] must be of type (string | int | false)");
+    });
+    
+    test('surfaces missing key error from array shape inside union', function () {
+        expect(fn() => testDeepUnionError(['id' => 10]))
+            ->toThrow(\TypeError::class, "Argument \$payload is missing required key 'tags'");
+    });
+
+    test('surfaces deep object shape error inside union using anonymous class', function () {
+        $user = new class {
+            public int $id = 10;
+            public object $profile;
+
+            public function __construct() {
+                $this->profile = new class {
+                    public string $name = ''; 
+                };
+            }
+        };
+
+        expect(fn() => testDeepObjectShapeUnion($user))
+            ->toThrow(\TypeError::class, "Argument \$user->profile->name must be of type non-empty-string");
+    });
+
+    test('surfaces missing property error on object shape inside union using anonymous class', function () {
+        $obj = new class {
+            public int $id = 10; 
+        };
+
+        expect(fn() => testMissingObjectPropertyUnion($obj))
+            ->toThrow(\TypeError::class, "Argument \$data is missing required property 'role'");
+    });
+
+    test('surfaces uninitialized property error on object shape inside union using anonymous class', function () {
+        $obj = new class {
+            public string $name; 
+        };
+
+        expect(fn() => testUninitializedObjectPropertyUnion($obj))
+            ->toThrow(\TypeError::class, "Argument \$data property 'name' is uninitialized");
+    });
+
+    test('surfaces deep error in nested discriminated union shape', function () {
+        $payload = [
+            'type' => 'A',
+            'data' => ['score' => -5], 
+        ];
+
+        expect(fn() => testDiscriminatedUnionDeepError($payload))
+            ->toThrow(\TypeError::class, "['score'] must be of type positive-int");
+    });
+
+    test('surfaces deep error on class property with union shape', function () {
+        $fixture = new PropertyUnionFixture();
+
+        expect(fn() => $fixture->settings = ['config' => ['enabled' => 'not_a_bool']])
+            ->toThrow(\TypeError::class, "Property PropertyUnionFixture::\$settings['config']['enabled'] must be of type bool");
+    });
+
+    test('falls back gracefully to generic union error when no deep branch matches structure', function () {
+        expect(fn() => testDeepUnionError('string_instead_of_array'))
+            ->toThrow(\TypeError::class, "must be of type (array{id: int, tags: list<(string | int)>} | null)");
+    });
+});
\ No newline at end of file