Originally Posted by
Enpoli
Yes, both Block and Barrier will prevent Injection from going through. I made a cancelaura macro I could pop at the last second, in case I screwed up and hit some mitigation out of habit. Boss damage from Rikkal is pretty insignificant so a few seconds without mitigation won't kill ya.
Another interesting note about the Injection mechanic: If you take consecutive stacks of Injection, then your debuff will refresh and you won't spawn any parasites. The debuff starts to really hurt when it stacks higher than 2 or 3. This can be good if you accidentally let one through but you don't mean to spawn parasites for a little while. It can also be done if you don't want to release any more parasites at all. If your debuff falls off after Rikkal is dead, you will not spawn any parasites. Just a nice little trick to help you recover if a Shield Barrier gets used up slightly to quickly or w/e the case may be.
Also, Avatar carries over into the scorpion transformation. If you want to pull some crazy numbers, hold Karoz while you're in the scorpion and just rotate externals to stay alive. Juggernaut trinket is really strong too for the healing effect. I usually do about 100M to Xaril, and we can push him with only 1 Activate Catalyst going out.