Is Armored Guardian legal in Standard, Modern, and Commander?

Armored Guardian is legal in: Legacy, Vintage, Commander.

Armored Guardian

Q: What type of card is Armored Guardian?

Armored Guardian is a Creature — Cat Soldier. Its oracle text reads: "{1}{W}{W}: Target creature you control gains protection from the color of your choice until end of turn. {1}{U}{U}: This creature gains shroud until end of turn. (It can't be the target of spells or abilities.) Power/Toughness: 2/5"