This goes double if their abilities synergize with other cards those decks are playing
With Timetwister, Force of Will, Mana Drain, Brainstorm, and Dig Through Time accounted for, what cards could possibly do justice to blues legacy?
If your opponents have creatures with reach or flying , your board wipes will take care of those to keep the battlefield free from blockers
Then whenever another permanent enters your battlefield, you reveal the top card of your library and you can draw it if it matches a permanent you control
Most Izzet generals tend to concentrate on either playing spells for reduced cost (Mizzix of the Izmagnus, Jhoira of the Ghitu), or being able to dig through the top of the library to get advantage or access to spells (Keranos, God of Storms, Melek, Izzet Paragon)
Muerra's first ability is not a mana ability