Omnicarnation

At the beginning of your precombat main phase,
if your devotion to colors is fifteen or greater,
add three mana of any color. This mana doesn't
empty from your mana pool as steps and phases
end.
Whenever a player casts an instant or sorcery
spell, you may pay that spell's mana cost. If you
do, create a copy of that spell. You may choose
new targets for the copy.