Luji, Piano-Wise

Whenever you cast a spell, put a number counter
on Luji, Piano-Wise, for the number of generic
mana in that card's mana cost, if there isn't
already a counter of that type on Luji, Piano-Wise.
(if a spell costs {1}{b}, you'd put a {1} counter on Luji,
Piano-Wise)
{w}{u}{b}{r}{g}: Remove all number counters from
Luji, Piano-Wise. If 7 or more different counters
were removed this way, add {w}{w}{u}{u}{b}{b}{r}{r}{g}{g} and draw seven cards.