Removal like Lightning Axe and Path to Exile, draw spells like Chart A Course, and cards that provide extra turns such as Temporal Tresspass are some of the best targets you can find
However, you can't have a creature with power 2 or less enter and try to raise its power with a spell, an activated ability, or a triggered ability
In an older Standard, Cast Out was a similar removal spell that had Flash
(Each in the mana costs of permanents you control counts toward your devotion to blue.) Creature - Wizard Merfolk The One Ring Indestructible When The One Ring enters, if you cast it, you gain protection from everything until your next turn
His inspiration for making it a proofreader came from the white activation that deleted letters from the names of permanents (the original version just hit permanents, but Ari later came up with the idea of adding players, as that seemed like it could lead to some fun interactions)