Kayn, The Shadow Reaper

Anytime Kayn, The Shadow Reaper deals damage to a player put a Darkiin counter on Kayn. Anytime Kayn deals damage to a creature put a Shadow token on Kayn.
When Kayn has 3 of either counter sacrifice Kayn and create a Rhaast Token if the counters are Darkiin, or sacrifice Kayn and create a Shadow Assassin token if the counters are Shadow.