If you want to use this for Arena, I would suggest building a little more control.
There are 3 things that you are bound to run into that will hurt you big time, and their easy counter
1)Shields, especially dmg (fire/thorn carapace) and dim shields.-Momentums
2)Black Hole, the bane of all rainbow decks.-Sanctuary
3)Otyughs, another thing that destroys rush decks if it gets out fast.-Lobotomizer (Ulitharid could work, but its more risky since its easier to kill)