Dwarven Power-ring

As long as dwarven power-ring is equipped to a
dwarf, dwarves you control get +1/+1 and have
Haste.
Equipped creature gets +1/+1. If equipped
creature is a dwarf, it gets +3/+3 instead.
Equipped creature has Trample and First strike.
There can be up to 7 cards in your deck named Dwarven power-ring.
Equip:{3}{r}{g}
Equip dwarf:{1}{r}{g}