I'm fairly new to this as well. I understand Mega is its own thing with gameplay changes, but what's the difference between Revival (This thread), and the one linked in the OP for Mega for gen 3 patches? This one:
I loaded up both with a complete Pokedex save and some of the sprites are different. Sharpedo being the first one that comes to mind. "The Other Moemon Ports" thread version seems to match sprites from the Mega ROM (the one where she looks more like a cop, almost), while the download from this thread seemed to be an older one. Yet this thread is more active.
Changelog on OP for this topic's last update is 9-11-2016 and from "The Other Moemon Ports" thread it seems the last update was April 21, 2018
Can someone fill me in?