Source: Wikipedia, "Bloodwych," available under the CC-BY-SA License.
The game had an add-on pack released called Bloodwych: Data Disks Vol 1 (also known as Bloodwych: The Extended Levels). Among the features of the add-on pack was the capability to persuade some of the enemy creatures to join your "merry band".
User Summary - from the back of the game box
Just when you thought you'd won! In the final battle of Bloodwych, the Lord of Entropy was not in fact killed, he was merely 'ejected' from our world into his own. To take revenge he has summoned you to his world, where he has created a new dungeon that makes Treihadwyl seem like a holiday camp. Fail in your quest to banish him and he will feast, slowly on your soul.
- A whole new class of spells
- Recruitable monsters
- Enhanced graphics communication and gameplay
- Over 25 new levels to explore
- Intriguing new puzzles
- Fiendish new monsters