If we're feeling safe on the field and there's no threat we want or can't remove, OP02-096-kuzan can be a choice to play for draw value
That's one crisis averted
Burning Earth Burning Earth is slow but annoying, and it's going to deal a lot of damage to everyone in the long run
We also have Tangled Colony, Nezumi Linkbreaker, Nezumi Informant, and Gnawing Vermin as cheap options
Delve has been printed on creatures, instants, and sorceries so far, and we could see it on other permanent types in the future, but Teval, Arbiter of Virtue gives it to all your spells
You get to use its activated ability three times in a game over the course of several turns