Unholy Infusion

For this part of the Shadowmourne quest, you must be the abomination in the Professor Putricide encounter. In order to infuse Shadow's Edge you must be 1. having it equipped
2. Have 100 Energy 3. Estimating when to use the skill. As the skill cost 100 energy, that makes you'll be entirely wiped out on energy to unable to slow an ooze. Also the ability has a cast timer so you can't do it with any slime puddles up. After you use the ability, you will gain "Unholy Infusion" buff for 6 minutes. Death will remove this buff and you must kill Professor with the buff in order to get the quest finished.
Disc priests and Resto druids spec'd into revitalize will give energy back to the abomination. When you are using the skill, make sure the priest cast the bubble early for it to wear off in time and have your resto druid spam Rejuv and Wild Growth on you.
Using Unholy Infusion at 50% seems to be the best time.