William Chu is tRoLliNg

The cost to summon this card is either or
. . If this card is cast to the battlefield without
paying its CMC: all unset, illegal, banned cards
become playable to all players.
{w}{u}{b}{r}{g}{t}: Add{w}{u}{b}{r}{g} to your mana
pool. You gain Deathtouch until the end of turn.
When William is trolling, he FuNCtioNs like a Black
Lotus and heals target when attacking (yep!). Those
5 colors there... are for good (no) reason!