Med bay

When tapped give {c} or retrieve exiled
Combat Miner with 5 counters on them.
While the Med Bay is is play, all Combat miners
gain: "If this creature is killed, exile it instead"
In your upkeep phase, add 1 counter to all
Combat Miners in exile. If a Combat Miner
gains 8 counters in this way they are destroyed.
That could have gone better!