Your biggest problem will be defending Teval, who has no protection against removal, will suffer when cards are exiled, and who must constantly jump into the fray of battle
So without being able to abuse its ability, or have it act as a commander, Kheru Lich Lord is a much overlooked card
Who wants to buy a new playmat each year because its been worn out from all the action it gets during games? Not us...and certainly not you, which is why we make it a point to craft these mats with premium materials, that way theyre truly made to last
If you'd like a deck built you can find me on Fiver.com as genoslugcs
Among main decks of Izzet Prowess builds specifically, 6 players are running four copies, 75 are running three copies, 32 are running two copies, 8 are running one copy, and 19 are running no copies of Vivi Ornitier
In a pinch, you can also sacrifice Kind Darien to protect your army from a board wipe or another type of targeted removal