The World Ender

This spell cannot be countered and costs {x} less
to cast, where X is the total mana value of
all equipped equipment you control.
Immediately activate the possession abilities of
any number of Darkin equipment you control
without paying their mana costs.
Until end of turn, all creatures you control gain
haste and have +X/+X where X is the number
of +1/+1 counters on target creature you control.