Mutliple Levels of Non-hero Abilities

I am making a druid hero class, which will be able to turn into bear form at the click of a button and revert back just as easily. The problem is, my max level for the heros is 30, and there is no way to balance just the standard one level bear form for 30 leves. Is there a way to make non-hero abilities have multiple levels? If not, is there another way this could be done aside from metamorphasis, because I want the player to be able to stay in bear form as long as they like. :(

To give perspective, I want about 6 levels of it, so I can make one different bear every 5 levels or so. If not bear form is going to be too great at low levels or terrible at higher ones.

Edit: Cannot spell... *sigh*

Makes it non-hero. This is Bear Forms default. Just switch it to this:

Sigh... I feel stupid, I have tried that many times before and it didn't work. This time however I clicked a different ability then clicked back to check it... sure enough... Thanks

O.O Still can't believe I have been missing that...