Anhelo, the Painter

Casualty was designed as a build-around: sacrifice a creature big enough to matter as you cast a spell, and the spell resolves twice. This commander broadens where that trade is available by stapling casualty 2 onto the first instant or sorcery you cast each turn, so the keyword stops being a printed property of specific spells and becomes something you supply to any spell you want. The sacrifice is still the price: you need a creature with power 2 or greater on hand, and giving one up is what buys the copy. What changes is the deckbuilding question. Instead of hunting for cards that were printed with casualty, you ask which spells you most want to cast in duplicate and which bodies you are willing to feed: a doubled removal spell splitting between two threats, a ritual run twice, a draw spell that refills into another draw spell. The 1/3 deathtouch body is the tell about how this deck actually wins. It is not a clock; it is a deterrent that keeps combat honest while the spell engine grinds, and it exists mostly to keep the commander on the battlefield, since the casualty grant only applies while it is there to hand out. The Grixis identity is the last piece: this is exactly the shard that stocks the tutors, the burn, and the disruption to make a doubled spell decisive rather than merely tidy.