Is Sigiled Sentinel legal in Standard, Modern, and Commander?

Sigiled Sentinel is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic.

Sigiled Sentinel

Q: What type of card is Sigiled Sentinel?

Sigiled Sentinel is a Creature — Human Knight. Its oracle text reads: "Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.) Vigilance"

Creature — Human Knight

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)

Vigilance

Set March of the Machine

Rarity Common

Mana Value 3

Artist Volkan Baǵa

Collector # 37

Scryfall Gatherer