The first of these paths is to stick entirely to on-theme cards, i.e., other Marvel universe cards
95% of the time, the triggered ability probably isnt worth a removal spell thats going to be better sent towards Rhystic Study or Smothering Tithe, but once enough cards have been exiled, the risk from rolling a 20 is going to weigh on your opponents
It lets you get to your massive threats a little bit faster, which is exactly what green decks want to do
Put a stun counter on either of them
One other subtle strength here is the degree of control you can have over exactly when cards are milled, and how many (assuming you have painlands or other unrestricted self-damage sources)
Ad Nauseam [Game-Ending Combo Enabler] Ad Nauseam trades life for raw access at instant speed