Ratadrabik of Urborg + Leyline of Singularity + Dimir House Guard

Ratadrabik of Urborg

Leyline of Singularity

Dimir House Guard

How it works

1. Activate Dimir House Guard by sacrificing it.
2. When Dimir House Guard dies, Ratadrabik triggers, creating a token copy of Dimir House Guard that is a 2/2 legendary Zombie in addition to its other types.
3. Resolve the Dimir House Guard ability.
4. Repeat using the Dimir House Guard token

This clever engine relies entirely on Leyline of Singularity's global enchantment effect, which turns every single nonland permanent on the battlefield into a legendary creature. With that foundation set, sacrificing Dimir House Guard to its own regeneration ability sends it to the graveyard, triggering Ratadrabik of Urborg to create a non-legendary 2/2 black Zombie token copy of it. Because Leyline of Singularity makes that new token legendary as well, the copy can also be sacrificed to Dimir House Guard's activation, allowing you to loop the process indefinitely for infinite entry, leave-the-battlefield, death, and sacrifice triggers.