It's pretty infuriating that several characters have waited for enough people to take on this bounty and then when it's over it acts like I didn't do anything. It still says Defeat Metahuman Experiment. He did attack me, he knocked me out but I was picked up and continued, so I know I was in the battle, but he fell and... nothing
When BOP first came out, it gave you a reward just by participating. But something seemed to have changed where if you are not in the battle before his minions come out, then you get nothing. At least that has been happening to my alts when battling him. The Shadow Golem worked this way so it was nice to complete this mission. I dont like it when they restrict you with some hidden rule where you get nothing because of <some reason X...>
When you do world bosses go to lfg chat and type "***** spam phase"(replace **** with boss name) although there isn't a kill count for meta there are double marks and its a quick 16 so yes people wil come. Little trick i learned works for almost every weekly open world boss.