Dominaria

Benalish Marshal | Creature | Human Knight | Other creatures you control get +1/+1. | Mark Zug

D'Avenant Trapper | Creature | Human Archer | Whenever you cast a historic spell, tap target creature an opponent controls. (Artifacts, legendaries, and Sagas are historic.) | Winona Nelson

Danitha Capashen, Paragon | Legendary Creature | Human Knight | First strike, vigilance, lifelink Aura and Equipment spells you cast cost {1} less to cast. | Chris Rallis

Dub | Enchantment | Aura | Enchant creature Enchanted creature gets +2/+2, has first strike, and is a Knight in addition to its other types. (It deals combat damage before creatures without first strike.) | Bastien L. Deharme

History of Benalia | Enchantment | Saga | (As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I, II — Create a 2/2 white Knight creature token with vigilance. III — Knights you control get +2/+1 until end of turn. | Noah Bradley

Invoke the Divine | Instant | | Destroy target artifact or enchantment. You gain 4 life. | Magali Villeneuve

Pegasus Courser | Creature | Pegasus | Flying Whenever Pegasus Courser attacks, another target attacking creature gains flying until end of turn. | Mathias Kollros

Sergeant-at-Arms | Creature | Human Soldier | Kicker {2}{W} (You may pay an additional {2}{W} as you cast this spell.) When Sergeant-at-Arms enters the battlefield, if it was kicked, create two 1/1 white Soldier creature tokens. | Scott Murphy