Is Shauku, Endbringer legal in Standard, Modern, and Commander?

Shauku, Endbringer is legal in: Legacy, Vintage, Commander.

Shauku, Endbringer

Q: What type of card is Shauku, Endbringer?

Shauku, Endbringer is a Legendary Creature — Vampire. Its oracle text reads: "FlyingShauku, Endbringer can't attack if there's another creature on the battlefield.At the beginning of your upkeep, you lose 3 life.{T}: Exile target creature and put a +1/+1 counter on Shauku."

Legendary Creature — Vampire

Flying<br>Shauku, Endbringer can't attack if there's another creature on the battlefield.<br>At the beginning of your upkeep, you lose 3 life.<br>: Exile target creature and put a +1/+1 counter on Shauku.