Ball of lightning is free and so is bone catcher. I feel ball of lightning might screw up the mulligan. Also Ball of lightning makes this a Duo deck even though it cost nothing it is still from the Aether element.
Take them out if you want it to be mono and draw bonecatcher more in your first hand.
Use the unupped version of retro virus, it only cost 1 so you will not poison everything but you will have your deck go off on the second turn instead of the third. ( That is if you keep or take out ball of lightning. )
I feel like you should take out a Bonedragon for a bonewall. It can buy you a turn or more, and that gives you 1 more turn to win.
If you want mono
- 6 retro for thier unupped version
-1 dragon for a bonewall
With these changes you get your deck 1 turn faster but give up the ability to poison thier whole field. Also you add defense as well with the bonewalls, and you fix the mulligan issue.
Also incase you don't know elements has a mulligan, if you don't draw any free to play cards in your first hand it randomly gives you another hand, but it only dose this once. So ball of lightning can screw things up.
Also do not underestimate bonewall, when your opponet tries to steal it or use perm control it will only destroy 1 bone counter. Save a virus for later when you get bonewall and you should win. Also it combos well with arsenic.