With the Soul of Wolf relic, you will be able to take the shape of a wolf. This is the first form you should come across. It is a good form for getting into smallplaces that Alucard cannot as a man. But once you get the Bat or Mist form, this one really begins to lack. With the other relics for the wolf, you will be able to run faster, and perform a special attack.

Once you get the Soul of Bat relic, you will be able to fly anywhere in the castle. This is great for getting to those out of reach places, or getting past some enemies. When you obtain the other relics for your bat form, you can then shoot fireballs, light up dark areas with your sonar, and even damage enemies with the sonar. Overall, a pretty descent form to have.

The Form of Mist relic is truly the best of the best to get. With this, you will be able to transform into a mist cloud, and pass through holes, and cages. With the power of mist, you will be able to remain as mist, until you run out of magic. This gives you the ability to get by anyone, and get anywhere you want to go. But this is still not the end of it... Once you have defeated Galamoth in the second half of the game, you will gain access to the Gas Cloud relic. With this awesome relic, your mist will damage any enemy that comes into contact with it! Truly this is the mother of all your forms, and is so worth getting.