Four Artifact Weapons (Charon Prime)

1. Ornate long rifle made of brass-like metal. It has wide, rectangular barrel. If fired, emits low, howling sonic wave, dealing 1d12 damage. Unfortunately, each shot damages weapon's operator as well, if his / her ears are unprotected (1d4 damage). It's possible that people / creatures near the target will receive some damage as well. Weapon don't use any ammo - can shoot 1d8 times and after that it must recharge for 20 minutes.
2. Strangely carved ash-gray sword made of warm metal. If wielded, it attaches itself with wielder's hand and connects with his / her neural network. It should be treated as +4 weapon, also sword's wielder gains additional 13 HP (which can be regenerated much faster than natural Hit Points, in example one per hour). Unfortunately, after seven weeks swords takes over its victim, transforming him into some untold, alien monster. Effects of this transformation are not instant but in the first phase (six weeks) only internal organs, muscles and bones are affected by changes. Sword can be removed only with whole arm and only during first week of it's "parasitic state". Later changes made by it are too big and victim dies within d6 hours if separated from the blade.
3. Seven-fingered gauntlet (with two thumbs and one really long middle finger) made of some kind of chitinous material. It can't be used without merging itself with operator's body, but will not connect with undamaged human flesh - arm must be seriously mutilated (in example flayed, with fingers broken etc.) before connection. After merging, arm is very quickly healed, but now its shape fits to the gauntlet. Gauntlet can be used in melee combat (it deals 1d8 damage), also it shoots bolts of raw, destructive energy (1d20 damage, range about 50 meters) but it draws it from user's body (5 HP per shot). Except horrible deformation (or maybe mutation) of victim's hand, gauntlet has no other unsettling abilities, however, if it's not worn on deformed hand for at least two hours per day, victim may have strange sensations, similar to alien hand syndrome.
4. Jet-black sphere covered with geometric carvings. It can be activated with electricity or heat (torch isn't enough, campfire or burning gas canister is better). Once activated, it automatically deactivates after 3d4 cycles and cannot be used for the next five days. Once per five rounds it sends circular wave of energy, draining life force from every living being in 50 meters radius (but probably there are some bigger spheres, with larger range). Each wave drains d4+2 HP. If any living being drops unconscious, after one round it raises from the ground and its body is controlled by the sphere, but remember that it's the alien artifact and something may just go wrong (victims may attack, perform, strange things or even try to eat themselves alive.