A team of
- something that converts to yellow or purple, to get it started, preferably not using that color
- Moloch (third trait) and/or Plague (third trait)
- doesn't matter
Would then be able to win rather easily I think. Just ensure either yellow or purple is the most plentiful and keep chaining Coatl into itself, regardless of its mana cost (as long as it isn't outrageous like 30, and even then).
There's a reason Anu's Sceptre can't destroy blues (which it should state, btw).