Kor Duelist

As long as Kor Duelist is equipped, it has double strike. (It deals both first-strike and regular combat damage.)

Puresteel Paladin

Whenever an Equipment you control enters, you may draw a card.
Metalcraft — Equipment you control have equip {0} as long as you control three or more artifacts.

Champion of the Flame

Trample
Champion of the Flame gets +2/+2 for each Aura and Equipment attached to it.

Colossus Hammer

Equipped creature gets +10/+10 and loses flying.
Equip {8} ({8}: Attach to target creature you control. Equip only as a sorcery.)