Is Discordant Spirit legal in Standard, Modern, and Commander?

Discordant Spirit is legal in: Legacy, Vintage, Commander.

Discordant Spirit

Q: What type of card is Discordant Spirit?

Discordant Spirit is a Creature — Spirit. Its oracle text reads: "At the beginning of each end step, if it's an opponent's turn, put a +1/+1 counter on Discordant Spirit for each 1 damage dealt to you this turn.At the beginning of your end step, remove all +1/+1 counters from Discordant Spirit."

Creature — Spirit

At the beginning of each end step, if it's an opponent's turn, put a +1/+1 counter on Discordant Spirit for each 1 damage dealt to you this turn.<br>At the beginning of your end step, remove all +1/+1 counters from Discordant Spirit.

Set Mirage

Rarity Rare

Artist Alan Rabinowitz