Niv-Mizzet, Visionary

Double strike (This creature deals both first-strike and regular combat damage.) Vigilance (Attacking doesn't cause this creature to tap.) Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Creatures you control get +1/+1.

When Kiora enters, draw two cards, then discard two cards. Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Trample Whenever this creature attacks, another target creature you control gains trample and gets +X/+X until end of turn, where X is this creature's power.

T: Add CC.

Flying You have no maximum hand size. Whenever a source you control deals noncombat damage to an opponent, you draw that many cards.

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead. If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Put all creature cards from all graveyards onto the battlefield under your control.