My take on what to do if you want to use Arcane Strike. be a bloodrager. Full caster level progression, full BAB, good stat priorities, rage for better strength, and the bloodrager specific feat Blooded Arcane Strike. That last one gets rid of the swift action requirement as long as you are bloodraging. It is also good if your build is a Vital Striker with the Blooded Arcane Strike feat. A natural attacker also benefits from having all attacks deal the extra damage. Still, I'm not telling you what to do, just a suggestion.