Dominaria

Helm of the Host | Legendary Artifact | Equipment | At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste. Equip {5} | Igor Kieryluk

Thran Temporal Gateway | Legendary Artifact | | {4}, {T}: You may put a historic permanent card from your hand onto the battlefield. (Artifacts, legendaries, and Sagas are historic.) | Jason Felix

Traxos, Scourge of Kroog | Legendary Artifact Creature | Construct | Trample Traxos, Scourge of Kroog enters the battlefield tapped and doesn't untap during your untap step. Whenever you cast a historic spell, untap Traxos. (Artifacts, legendaries, and Sagas are historic.) | Lius Lasahido