Ojutai, the Skywise

Flying, Prowess. (Whenever you cast a noncreature spell, this creature gets +1/+1
until end of turn.)
Whenever Ojutai, the Skywise attacks, you
may pay {w/u}{w/u}{w/u}{w/u}. If you do, creatures you control gain flying and get +1/+1 until end
of turn.