Flameskull

Flying
This creature can't block.
Rejuvenation — When this creature dies, exile it. If you do, exile the top card of your library. Until the end of your next turn, you may play one of those cards. (If you cast Flameskull this way, you can't play the other card, and vice versa.)

Glarewielder

Haste
When this creature enters, up to two target creatures can't block this turn.
Evoke {1}{R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Nova Chaser

Trample
Champion an Elemental (When this enters, sacrifice it unless you exile another Elemental you control. When this leaves the battlefield, that card returns to the battlefield.)

Ruby, Daring Tracker

Haste (This creature can attack and {T} as soon as it comes under your control.)
Whenever Ruby attacks while you control a creature with power 4 or greater, Ruby gets +2/+2 until end of turn.
{T}: Add {R} or {G}.