What's the reason for erasing their memories tho

Mc stuff☠

So he could live a normal life. Only he's a muscle head who can't think 2 seconds into the future. So he didn't realize that while he could alter everyone's memories of him, his actions still had a lasting impact on the world. Something that couldn't be erased.

In a way, this whole mess in season 2 is his fault. Had he not made Sys (her actual name, no idea why they started calling her sis...) erase everyone's memories of him none of the stuff in season 2 would have even happened...