So I've defeated 2 Bosses in WoL so far, both of which weakened Galeem's Shield Specifically. While I haven't gotten Darkon (or whoever it is) to appear yet, apparently you can't go too far against 1 or another to get the true ending. Is there any way I can guarentee I'll be safe for the true ending? I'm about to go to my 3rd boss area, but just wanna make sure of this ahead of time