Activate Woe Strider by sacrificing Gleeful Arsonist
When Gleeful Arsonist dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
Activate Woe Strider by sacrificing Gleeful Arsonist
When Gleeful Arsonist dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Resolve both Woe Strider abilities from step 1 and 3.
Repeat.
This clever engine turns Isilu, Carrier of Twilight's passive grant of persist into a perpetual motion machine by pairing it with Gleeful Arsonist's innate undying ability. When you feed Gleeful Arsonist to Woe Strider's sacrifice outlet, the opposing +1/+1 and -1/+1 counters cancel each other out upon subsequent resurrections, allowing the arsonist to die and return over and over again without ever permanently staying in the graveyard. Woe Strider even helps smooth your draws along the way with its scry ability, while Eirdu, Carrier of Dawn waits in the wings to shift the dynamic back whenever you need its convoke and lifelink capabilities.