Depending on how many shapes/forms you can polymorph into, maybe each shape could be tied to a specific attribute? If there is a light agile form, it could be tied to dexterity. If there is a hulking monstrosity, it could be tied to strength, and so forth.
That way polymorph will complement any particular play style without being gimp or OP on any character.
(oops, just a general reply, not directed at anyone specific)
Last edited by Halcyon; 28/01/16 08:12 PM.