 If you liked
Kouya ni Kemono Doukokusu
|
 ...then you might like
Gusha no Hoshi
|
Character design and art is definitely similar. The transformations are great though the storytelling is a little bit different.
The MC leads a difficult life due to being stronger than other 'mutants' based on genetics or lineage or a program.
<> Kouya ni Kemono: the MC is on his own, Gusha no Hoshi: the MC has comrades
<> Kouya ni Kemono: the MC can transform without other items, Gusha no Hoshi: MC needs an item to transform