This patch is meant to make the game a bit easier and less frustrating.
Applying this patch to Mega Man 6 will make the weapon energy of all weapons restore fully whenever a life is lost.
This mechanic is officially applied in Mega Man games for the PS1 and later.
ROM / ISO Information:
Database match: Mega Man 6 (USA)
Database: No-Intro: Nintendo Entertainment System (v. 20180803-121122)