The more mana you have, the more harrasment you can get off. The more harrasment means the less xp they will receive due to hiding and and going back to the pool for health. Plus, it really is a savior late game. =)

Well, its your first guide, so its really alright. You have a good english it is clear what you want to say and your intentions are mainly good. There are some points of criticism, for example in my opinion you dont need clarity although you explained well why you take it. Just never spam the Grab or Overdrive, then you can take Exhaust and a grabbed, exhausted target is more than a 100% safe kill ;)

Still making the Guide alot nicer. Adding pictures and colors instead of walls of Text. First Guide so still learning, Thanks for Reading!