My favorite use is to make an instant creature with an enters-the-battlefield (ETB) trigger
I want full control over what my cards sell for and when
It is possible to fall short damage-wise, though, so if you can't knock it out in one hit or get out a Mew or Mew-EX to attack it, it's best to focus on the benchwarmers or chip away at it with Galvantula since Damage Change can possibly be used thanks to Shrine of Memories to heal off any damage you deal
For example, Ghostfire Slice can target and deal damage to Auriok Champion, even with it having protection from red
Make spells cost more When you're chaining spells, even making someone pay 1 extra each time is rough
It brought cards up to the stage like Foster, as well as dipping into the vast array of obvious triggers and engines, from Goblin Bombardment to Fecundity