Coretapper

{T}: Put a charge counter on target artifact.
Sacrifice this creature: Put two charge counters on target artifact.

Shirei, Shizo's Caretaker

Whenever a creature with power 1 or less is put into your graveyard from the battlefield, you may return that card to the battlefield at the beginning of the next end step if Shirei is still on the battlefield.

Magistrate's Scepter

{4}, {T}: Put a charge counter on this artifact.
{T}, Remove three charge counters from this artifact: Take an extra turn after this one.