This is straight up bad game and event design, i'm all for "chase" things, but a non instanced boss that takes half an hour to get low enough with a group to tame him and then have him tamed by a guy hopping channels is not good. Not to mention that it's pretty much one large guild farming him 24/7 so other people don't even get a chance.
Remove his hp requirement, make him spawn more than 12 times a day, or straight up remove his requirement for the event.
Remove his hp requirement, make him spawn more than 12 times a day, or straight up remove his requirement for the event.