PvE hackapel2: difficult to play hacka with just sword investment. Need at least 2 weapon-investment.
Currently XXX fletcher3 hacka2 is strong because fletcher was buffed.
End gear qs3 fletcher3 hacka2 vs dragon video here. Need investment into crossbow and sword. Qs could use crossbow + shield and leave sword on auto-weapon swap to stay defensive. A lot of skills to use, SP cost is high.
Reiter 1 + hacka2 still strong sustained damage. Good value with a lot of line-buffs and elemental buffs from party. Mainly investment into sword, and some into gun. If you rely on +elemental damage and extra lines, gun investment may be low. Press limacon-C a lot and hacka skills for burst.
Ranger3 rogue1/2/3 hacka2 build still doing ok. A bit better at AoE after ranger patch. Need crossbow and sword investment.
For PvP need qs1 for quarrel shooter shield passive. And sapper detonate traps is good at PvP too. But archer PvP is difficult.