Mercury Hammer

When Mercury Hammer enters the battlefield,
you may pay {3}. If you do, create a Gemstone
token. (It's an artefact with "{t}: add one mana of
any colour.")
Equipped creature gets +5/+5 and has reach .
{3}, Tap an untapped Gemstone token you
control: Equip Mercury Hammer to target
creature you control. Activate only as a sorcery.