Saimu, The Debtless

During your upkeep all opponents loss {x} life
and you gain life equal to the life lost this way.
Whenever you gain life add in any
combination of {b} and/or {w} mana to
your mana pool.
{x}{b}{w}, search your library for a "Thrull"
card with converted {x} or less then if {x} is six or
more
cast target "Thrull" from your hand with
converted
mana cost {x} or less.