True. But Vampire already has to take a level to get 100% healing, and it has to take a level to become a mutation before it can get steal as an ability, otherwise you have to take it as a spell, which is no fun =(
Leveling explained!
Every level you get a level point. They may be spent in one of four ways.
For 1 level point, you may take a passive ability. Water breathing, fireproof, airbourne, immune to poison, night vision, whatever.
For 1 level point, you may upgrade an ability. Every ability has 1-4 upgrades to it. Vampire can upgrade healing due to damage. The EXCEPTION to this rule is poison/alchemy, which are learned through more active abilities.
For 2 level points, you may learn a spell from the game. Like in game, each spell gets 6 uses per day.
For 2 level points, you may learn an active ability. You may NOT have two active abilities. Some abilities require other active abilities.