Is Belbe, Corrupted Observer legal in Standard, Modern, and Commander?

Belbe, Corrupted Observer is legal in: Legacy, Vintage, Commander.

Belbe, Corrupted Observer

Q: What type of card is Belbe, Corrupted Observer?

Belbe, Corrupted Observer is a Legendary Creature — Phyrexian Zombie Elf. Its oracle text reads: "At the beginning of each postcombat main phase, the active player adds {C}{C} for each of your opponents who lost life this turn. (Damage causes loss of life.)"

Legendary Creature — Phyrexian Zombie Elf

At the beginning of each postcombat main phase, the active player adds for each of your opponents who lost life this turn. (Damage causes loss of life.)