Yahenni, Undying Partisan

Each player sacrifices all permanents they control that are one or more colors.

Flying, double strike, vigilance, trample, indestructible

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time. Creature tokens you control have vigilance and lifelink.

Haste R, T: Create a 3/1 red Elemental creature token with haste.

Equipped creature gets +1/+1. Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Equip 2

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way. Cycling 3BB (3BB, Discard this card: Draw a card.) When you cycle this card, all creatures get -2/-2 until end of turn.

(T: Add R.)

This land enters tapped unless you have two or more opponents. T: Add G or U.