Assembler of the Damned

At the beginning of your end step, remove a reassembly counter from each phased out
creature you control.
Reassemble {1}{b} (Whenever this creature dies, you
may pay {1}{b}. If you do, return it to the battlefield
phased out under your control with 3 reassembly
counters on it. As long as it has a reassembly counter
on it, it doesn't phase in. At the beginning of your
upkeep, remove a reassembly counter from it. When
the last is removed, it phases back in.)