There are also options to increase your opponents' life loss
You cant touch Treeborn Frog with your Caius, since it will always be in the graveyard, and you cant answer the monarchs until after theyve used their effects and attacked, since theyll be in the hand before then
I love this in the 99 of aggro decks like Boros Aggro, or goad brews that want to force attacks like the first one for triggers, or cast from exile triggers like Rakdos's Prosper, Tome-Bound or well, you can see the synergies, card flow and forced attacks this little boy can do and he drops before real counters are on line or are immune to them like Swan Song or Negate or An Offer You Can't Refuse
"Raviel, Lord of Phantasms", "Uria, Lord of Searing Flames" and "Hamon, Lord of Striking Thunder"
"Bujin Hirume", based on Alexis Rhodes
But Izzet is diverse, so in terms of the archetype she represents, I dont see her losing her place as the spells matter general of choice