It might be a bug, but is not what is stated here.Simply, mephisto is gaining power due to the opponent mephisto aura of incineration
Any incenerate does that to Mephisto its his ability description is "generates 12% of a power bar per second instead of taking incenerate energy damage" so your aura gives him aura. But he is bugged in that video as it triggers while far away as aura doesn't reach that distance.
Any incenerate does that to Mephisto its his ability description is "generates 12% of a power bar per second instead of taking incenerate energy damage" so your aura gives him aura. But he is bugged in that video as it triggers while far away as aura doesn't reach that distance. That’s the whole point of this post.