Oguros, Apex of Evolution

Mutate {w}{u}{b}{r}{g}
Shroud
Oguros has all abilities of all cards on the battlefield and all cards in graveyards.
If an ability would require Oguros to mutate to activate, it instead requires Oguros to attack.
The number of times Oguros has attacked substitutes for the number of times it has mutated.
No creatures may mutate onto Oguros.
There comes a time when nature can offer no more