@Khaikaa I somehow already did what I want, not the way I want but its "working"... xD
@The Bunny Gamer The way I did it's working "fine", players must fight in 2 fronts, kill the mob to get inside him (one by one) and then break his heart! xD
@Dashplant In my case there's a lot of mobs inside with "one hit kill" projectiles as a "body defense system"
So if player don't break the herat he will die soon or later... xD
Even if player manage to don't die an auto event is started when the heart is killed, after 30s every player is send outside anyway!