Hm, I dunno, how about this?

-Monster Mark's HP increased
-When Hunt Monster spawns in the world there is a 5-10 min shield up on the monster that it receives no dmg until timer is up. (That way people have plenty of time to teleport in location and get to the monster without some impatient player just wanting to get the marks and get to the next location.)
-When Hunt Monster spawns, an NPC would shout something along the lines, "HELP!!! THE TERRIBLE "NAME" IS DESTROYING THE AREA @ <pos>." (So people don't use 3rd party sites to see if a mark is up.)