Event bosses

[Vexaril]

I like the idea of an event boss. I do not, however, like the idea of infinite hp. Why is this monster dying with infinite hp? I think if there is an event boss it should have a set amount of high hp, and when its killed, players that contributed a higher amount of damage should be given a higher chance of better rewards, but not a 100% chance. This way lower levels still have a chance to get rewards, but the higher levels that have spent more time playing the game and do more damage, have a better chance to get them.