They may seem to be nerfed but if you play them differently than the Vanilla weapons they are still very strong.

Scorpion: Raven or Gungnir can't go through any obstacle, and inflict damage to "infinite" number of limbs if all of them are in same trajectory

Rebuke: after shredding, fire is pretty OP, with that radius

Scyther: can finish many enemies, and destroy limbs, they will bleed out without attacking, good synergy good Killer Instinct for more attacks

Reaper: Vampiric is unvaluable, a bonus that provides HP without spending AP

Shard Gun: on top of regular damage, it synergizes with panic tactics like screaming or induce panic, also with mind control, because every attack is -12 WP for the enemy.

Crystal Crossbow: 40 piercing is great mid to late game and 60 damage synergizes with surprise attack and neural feedback

And take into account you save resources, and infinite ammo, and more slots in the backpack for other stuff