diff --git a/Source/Core/DiscIO/Blob.h b/Source/Core/DiscIO/Blob.h
index aa5274618a..473aa9bfce 100644
--- a/Source/Core/DiscIO/Blob.h
+++ b/Source/Core/DiscIO/Blob.h
@@ -70,7 +70,11 @@ public:
     return Common::FromBigEndian(temp);
   }
 
-  virtual bool SupportsReadWiiDecrypted() const { return false; }
+  virtual bool SupportsReadWiiDecrypted(u64 offset, u64 size, u64 partition_data_offset) const
+  {
+    return false;
+  }
+
   virtual bool ReadWiiDecrypted(u64 offset, u64 size, u8* out_ptr, u64 partition_data_offset)
   {
     return false;
diff --git a/Source/Core/DiscIO/DirectoryBlob.cpp b/Source/Core/DiscIO/DirectoryBlob.cpp
index 77ca32d19b..1e06dd74bd 100644
--- a/Source/Core/DiscIO/DirectoryBlob.cpp
+++ b/Source/Core/DiscIO/DirectoryBlob.cpp
@@ -406,25 +406,33 @@ bool DirectoryBlobReader::Read(u64 offset, u64 length, u8* buffer)
       .Read(offset, length, buffer);
 }
 
-bool DirectoryBlobReader::SupportsReadWiiDecrypted() const
+const DirectoryBlobPartition* DirectoryBlobReader::GetPartition(u64 offset, u64 size,
+                                                                u64 partition_data_offset) const
 {
-  return m_is_wii;
+  const auto it = m_partitions.find(partition_data_offset);
+  if (it == m_partitions.end())
+    return nullptr;
+
+  if (offset + size > it->second.GetDataSize())
+    return nullptr;
+
+  return &it->second;
+}
+
+bool DirectoryBlobReader::SupportsReadWiiDecrypted(u64 offset, u64 size,
+                                                   u64 partition_data_offset) const
+{
+  return static_cast<bool>(GetPartition(offset, size, partition_data_offset));
 }
 
 bool DirectoryBlobReader::ReadWiiDecrypted(u64 offset, u64 size, u8* buffer,
                                            u64 partition_data_offset)
 {
-  if (!m_is_wii)
+  const DirectoryBlobPartition* partition = GetPartition(offset, size, partition_data_offset);
+  if (!partition)
     return false;
 
-  auto it = m_partitions.find(partition_data_offset);
-  if (it == m_partitions.end())
-    return false;
-
-  if (offset + size > it->second.GetDataSize())
-    return false;
-
-  return it->second.GetContents().Read(offset, size, buffer);
+  return partition->GetContents().Read(offset, size, buffer);
 }
 
 bool DirectoryBlobReader::EncryptPartitionData(u64 offset, u64 size, u8* buffer,
diff --git a/Source/Core/DiscIO/DirectoryBlob.h b/Source/Core/DiscIO/DirectoryBlob.h
index 9e6a834151..ca1f68d6ae 100644
--- a/Source/Core/DiscIO/DirectoryBlob.h
+++ b/Source/Core/DiscIO/DirectoryBlob.h
@@ -157,7 +157,7 @@ public:
   DirectoryBlobReader& operator=(DirectoryBlobReader&&) = default;
 
   bool Read(u64 offset, u64 length, u8* buffer) override;
-  bool SupportsReadWiiDecrypted() const override;
+  bool SupportsReadWiiDecrypted(u64 offset, u64 size, u64 partition_data_offset) const override;
   bool ReadWiiDecrypted(u64 offset, u64 size, u8* buffer, u64 partition_data_offset) override;
 
   BlobType GetBlobType() const override;
@@ -185,6 +185,8 @@ private:
   explicit DirectoryBlobReader(const std::string& game_partition_root,
                                const std::string& true_root);
 
+  const DirectoryBlobPartition* GetPartition(u64 offset, u64 size, u64 partition_data_offset) const;
+
   bool EncryptPartitionData(u64 offset, u64 size, u8* buffer, u64 partition_data_offset,
                             u64 partition_data_decrypted_size);
 
diff --git a/Source/Core/DiscIO/VolumeWii.cpp b/Source/Core/DiscIO/VolumeWii.cpp
index db31530c8e..2f0c833549 100644
--- a/Source/Core/DiscIO/VolumeWii.cpp
+++ b/Source/Core/DiscIO/VolumeWii.cpp
@@ -171,11 +171,9 @@ bool VolumeWii::Read(u64 offset, u64 length, u8* buffer, const Partition& partit
     return false;
   const PartitionDetails& partition_details = it->second;
 
-  if (m_reader->SupportsReadWiiDecrypted())
-  {
-    return m_reader->ReadWiiDecrypted(offset, length, buffer,
-                                      partition.offset + *partition_details.data_offset);
-  }
+  const u64 partition_data_offset = partition.offset + *partition_details.data_offset;
+  if (m_reader->SupportsReadWiiDecrypted(offset, length, partition_data_offset))
+    return m_reader->ReadWiiDecrypted(offset, length, buffer, partition_data_offset);
 
   if (!m_encrypted)
   {
diff --git a/Source/Core/DiscIO/WIABlob.cpp b/Source/Core/DiscIO/WIABlob.cpp
index 94c3fc12c3..bdeb3a2951 100644
--- a/Source/Core/DiscIO/WIABlob.cpp
+++ b/Source/Core/DiscIO/WIABlob.cpp
@@ -413,28 +413,55 @@ bool WIARVZFileReader<RVZ>::Read(u64 offset, u64 size, u8* out_ptr)
 }
 
 template <bool RVZ>
-bool WIARVZFileReader<RVZ>::SupportsReadWiiDecrypted() const
+const typename WIARVZFileReader<RVZ>::PartitionEntry*
+WIARVZFileReader<RVZ>::GetPartition(u64 partition_data_offset, u32* partition_first_sector) const
 {
-  return !m_partition_entries.empty();
+  const auto it = m_data_entries.upper_bound(partition_data_offset);
+  if (it == m_data_entries.end() || !it->second.is_partition)
+    return nullptr;
+
+  const PartitionEntry* partition = &m_partition_entries[it->second.index];
+  *partition_first_sector = Common::swap32(partition->data_entries[0].first_sector);
+  if (partition_data_offset != *partition_first_sector * VolumeWii::BLOCK_TOTAL_SIZE)
+    return nullptr;
+
+  return partition;
+}
+
+template <bool RVZ>
+bool WIARVZFileReader<RVZ>::SupportsReadWiiDecrypted(u64 offset, u64 size,
+                                                     u64 partition_data_offset) const
+{
+  u32 partition_first_sector;
+  const PartitionEntry* partition = GetPartition(partition_data_offset, &partition_first_sector);
+  if (!partition)
+    return false;
+
+  for (const PartitionDataEntry& data : partition->data_entries)
+  {
+    const u32 start_sector = Common::swap32(data.first_sector) - partition_first_sector;
+    const u32 end_sector = start_sector + Common::swap32(data.number_of_sectors);
+
+    if (offset + size <= end_sector * VolumeWii::BLOCK_DATA_SIZE)
+      return true;
+  }
+
+  return false;
 }
 
 template <bool RVZ>
 bool WIARVZFileReader<RVZ>::ReadWiiDecrypted(u64 offset, u64 size, u8* out_ptr,
                                              u64 partition_data_offset)
 {
+  u32 partition_first_sector;
+  const PartitionEntry* partition = GetPartition(partition_data_offset, &partition_first_sector);
+  if (!partition)
+    return false;
+
   const u64 chunk_size = Common::swap32(m_header_2.chunk_size) * VolumeWii::BLOCK_DATA_SIZE /
                          VolumeWii::BLOCK_TOTAL_SIZE;
 
-  const auto it = m_data_entries.upper_bound(partition_data_offset);
-  if (it == m_data_entries.end() || !it->second.is_partition)
-    return false;
-
-  const PartitionEntry& partition = m_partition_entries[it->second.index];
-  const u32 partition_first_sector = Common::swap32(partition.data_entries[0].first_sector);
-  if (partition_data_offset != partition_first_sector * VolumeWii::BLOCK_TOTAL_SIZE)
-    return false;
-
-  for (const PartitionDataEntry& data : partition.data_entries)
+  for (const PartitionDataEntry& data : partition->data_entries)
   {
     if (size == 0)
       return true;
diff --git a/Source/Core/DiscIO/WIABlob.h b/Source/Core/DiscIO/WIABlob.h
index 8f941ce98b..c76af169f2 100644
--- a/Source/Core/DiscIO/WIABlob.h
+++ b/Source/Core/DiscIO/WIABlob.h
@@ -59,7 +59,7 @@ public:
   std::string GetCompressionMethod() const override;
 
   bool Read(u64 offset, u64 size, u8* out_ptr) override;
-  bool SupportsReadWiiDecrypted() const override;
+  bool SupportsReadWiiDecrypted(u64 offset, u64 size, u64 partition_data_offset) const override;
   bool ReadWiiDecrypted(u64 offset, u64 size, u8* out_ptr, u64 partition_data_offset) override;
 
   static ConversionResultCode Convert(BlobReader* infile, const VolumeDisc* infile_volume,
@@ -224,6 +224,8 @@ private:
   bool Initialize(const std::string& path);
   bool HasDataOverlap() const;
 
+  const PartitionEntry* GetPartition(u64 partition_data_offset, u32* partition_first_sector) const;
+
   bool ReadFromGroups(u64* offset, u64* size, u8** out_ptr, u64 chunk_size, u32 sector_size,
                       u64 data_offset, u64 data_size, u32 group_index, u32 number_of_groups,
                       u32 exception_lists);
diff --git a/Source/Core/DiscIO/WiiEncryptionCache.cpp b/Source/Core/DiscIO/WiiEncryptionCache.cpp
index 0bb892da71..52d978761e 100644
--- a/Source/Core/DiscIO/WiiEncryptionCache.cpp
+++ b/Source/Core/DiscIO/WiiEncryptionCache.cpp
@@ -29,10 +29,7 @@ WiiEncryptionCache::EncryptGroup(u64 offset, u64 partition_data_offset,
 {
   // Only allocate memory if this function actually ends up getting called
   if (!m_cache)
-  {
     m_cache = std::make_unique<std::array<u8, VolumeWii::GROUP_TOTAL_SIZE>>();
-    ASSERT(m_blob->SupportsReadWiiDecrypted());
-  }
 
   ASSERT(offset % VolumeWii::GROUP_TOTAL_SIZE == 0);
   const u64 group_offset_in_partition =