Depopulate

Each player who controls a multicolored creature draws a card. Then destroy all creatures.

Zurgo Helmsmasher

Haste
Zurgo Helmsmasher attacks each combat if able.
During your turn, Zurgo Helmsmasher has indestructible.
Whenever a creature dealt damage by Zurgo Helmsmasher this turn dies, put a +1/+1 counter on Zurgo Helmsmasher.

Worldslayer

Whenever equipped creature deals combat damage to a player, destroy all permanents other than Worldslayer.
Equip {5} ({5}: Attach to target creature you control. Equip only as a sorcery.)

Shatter the Sky

Each player who controls a creature with power 4 or greater draws a card. Then destroy all creatures.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Raiyuu, Storm's Edge

First strike
Whenever a Samurai or Warrior you control attacks alone, untap it. If it's the first combat phase of the turn, there is an additional combat phase after this phase.