Since one of your goals is to turn your creatures into samurai, its a good idea to include samurai creatures with tribal abilities
This triggers an infinite loop in which damaging opponents gains you life, and gaining life damages your opponent
And we also have conceptual matches like Wall of Swords for the spell Blade Barrier, Chill Touch in D&D which drains spirit and soul vs Touch of Death, Return to Sand vs Return to Dust, Anti-Magic Aura vs Anti-Magic Shell, etc
This was the sacrifice needed to bring about the first Primal, and Magic: The Gathering players will have to do the same if they want the might of this being on their side
Taigam, Ojutai Master [Dragon deck]: That's one pair of awesome clauses
Generally it fails it killing everything that isn't attacking