Aura mode gives you 9 shots of a shoulder mounted cannon, which has multitargetting, ridiculously long charge time, long lock on time and moderate damage+homing, no benefit from EIW, generally isn't worth using seriously but a fun gimmick nonetheless.
And yes, Aura mode increases damage, previously there was a bug that have you KEEP the damage buff even after Aura ends, but I'm not sure if the bug is still present (probably is).
And yes STR/TEC affects his Aura the way they do for standard WBs.
Generally you shouldn't considering keeping TEC positive unless you do not wish to rely on the bug which gives him that extra damage permanently.
