Dragonhorn

As long as equipped creature is attacking, other creatures you control gain +1/+1, and have intimidate until end of turn. (This creature can't
be blocked except by artifact creatures and/or
creatures that share a color with it.)
Equip {1}{b} ({1}{b}: Attach to target creature you
control. Equip only as a sorcery.)
The Dragonhorn all but guarantees victory...
of course it makes no guarantee for the user...