Fabel, Mutated and Demented

Flash
You cant play Merfolk creatures as long as Fabel,
Mutated and Demented is in play
Sacrafice a Merfolk you control- Put a +1/+1
counter on Fabel, Mutated and Demented
Sacrafice a Merfolk you control- Remove all
counters on Fabel, Mutated and Demented
and return it to your hand