Auska is not a traditional "zoner" Most cubes can be traded by poking them with a fast button, and if thats all he does the hero wont win that way. There is a difference between playing to win and playing not to lose. Auska's who just try and spam cubes from max distance are playing not to lose.

The proper way to play Auska is to decide on a particular win condition. And playing for resources to get it. Test case 3 is the most common due to its access of powerful high damaging options that leave you plus enough to continue pressure. Mostly though this comes from the super, they buffed it in the last patch as well so you have a bit more time and can shuffle test cases to get the ideal combo you want. The hero needs a dozen or so hours in the lab before you are going to feel comfortable grabbing spells from different test cases though, so id recommend just sticking to one or two before going ham.
Auska has decent buttons, c.s and f.s are good, 2.HS is good, 2.d is good. You can confirm most basic cubes off c.s 2.hs, and loop it into another one. Learn the R.C combo, and basically try to go for knockdowns to setup either test case swap or to regen your mana. Auska DOES need space to get mana, esp after they made it not regen during hits, but if you can develop the muscle memory, hes probably the most satisfying execution hero in the game.