Forget about that color identity thing and just embrace Five Colors
Equip only as a sorcery.) Artifact - Equipment Artifact (CTRL to add secondary) Creature Ammit Eternal Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.) Whenever an opponent casts a spell, put a -1/-1 counter on this creature
Once youre done, you can save your design to your account, making it easy to return later and refine your card before printing
Additionally, this article may read a little weird to some people because, frankly, most of the creatures that you're playing in blink decks are quite affordable and budget-friendly
Without the other part of the card, this plan is simple: block the creature when it would deal more than 3 damage and don't block it when it would do less (all of this mitigated, of course, by when blocking it can kill it)
My enthusiasm for this form of Magic could not be greater