The Dragon's Graveyard

At the beginning of combat phase, choose a
creature. Search your library for a equipment
card, reveal it, and put it into battlefiald attached
on that creature. The chosen creature must attack
this turn. At the end of combat phase, shuffle
that equipment into your library. (Ignore tap
effects, summoning sickness and/or effects would make
that creature can't attack this turn.)
{t}: Each player adds {1} to their mana pool.