Infinite Corruptor

1. This is a timed event for him to spawn, you need to kill the first 3 bosses, talk to Arthas and fight through the gauntlet. Waiting for Arthas to help takes too long, so just run ahead.
2. You need to kill him within the 25 minutes, if you pull him and he is not dead in the 25 minutes then you're out of luck.
3. Basic tank and spank, just get him down before the 25 minutes is up. If the clock hits the limit he will walk back in his portal and leave. You can kill him while he is walking to the portal so try pulling him away from it for some extra seconds to finish him off.