Here's how it goes. Meadowboon can either be evoked in, or sacrificed to start the infinite. When this happens, I believe that both the "leaves the battlefield" and "dies" (with persist) triggers will go on the stack at the same time. I can then choose to have the persist trigger resolve first, putting the Meadowboon back on the battlefield. Then the "When this creature leaves the battlefield, put a +1/+1 counter on each creature target player (you) controls." will resolve which will buff your board, and also cancel out the -1/-1 counter from Meadowboon being Persisted. Allowing it to be repeated infinitely.
The cards involve Eirdu, Carrier of Dawn on the Persist granting side, Meadowboon, and any creature sac outlet of your choosing, lets just say Viscera Seer.
Here's how it goes. Meadowboon can either be evoked in, or sacrificed to start the infinite. When this happens, I believe that both the "leaves the battlefield" and "dies" (with persist) triggers will go on the stack at the same time. I can then choose to have the persist trigger resolve first, putting the Meadowboon back on the battlefield. Then the "When this creature leaves the battlefield, put a +1/+1 counter on each creature target player (you) controls." will resolve which will buff your board, and also cancel out the -1/-1 counter from Meadowboon being Persisted. Allowing it to be repeated infinitely.
Is this correct?
Thanks!