It's intended for PvE but it works in the arena well enough.
What works more effectly in the arena, according to what I think .. Are.APS and effects that focus on ignore resists and that also do pierce.
I'm not entirely certain where the line is Drawn when focusing on both ED% and pierce but from what I've experienced is that balancing both while having significant APS's works for all scenarios.
Movement speed Is also quite essential for the arena so keep that in mind, along with your disables.
Taunts and blinds Stand out most for me but it's mostly revolved around preference and how comfortable you are with your hero. Sometimes the statistics reflect that you shouldn't win a battle - how you use skill shots is what mostly predicts your wins. in my case Anyway.. tactfulnessforthewin.