What would you do To an ax7221?
What would I do? Well, I'd swap it for an RG, but assuming you have your heart set on the AX, the obvious answer is to replace the stock pickups.
To be honest I haven't heard the stock pickups so I'd give them a listen first. However, assuming they don't sound good, I'd put in replacements. Good choices would be Dimarzio Tone Zone 7 or Evo 7 pickups. From *Seymour Duncan, the Invader 7 or JB 7 picskups would do the trick. For extreme metal, I'd investigate putting in EMG-707 pickups. Installing EMG-707 will require routing the body.