[quote=Phobos]
Would it be fine to learn new magic while only in Take Over forms? I was planning onto giving Eren a Tengu form and giving it Wind Magic abilities, but only while he's in that form.
[/quote]

some basic magic but like I stated earlier, learning magic is a very hard and long process, taking up to several years of study for even basic magics so dont expect anything to powerful to quickly. However, seeing as Tengu have a natural affinity for wind magic it would not take nearly as long. On the other hand, learning a new take over can be hard as well and risky so be careful.