Should've had a look at this topic earlier but anyway...
I'm not a fan of the rifle. It fits a very narrow niche that would be better served if the pistol was buffed rather than creating a new weapon.
The nailgun works fine, though I do not like the sprite for it. It's overly small and is held in a manner that doesn't look comfortable at all.
Flamethrowers good, though I agree with the other guys that there needs to be a more solid sign of it doing damage.
The dark claw needs a colour change to differentiate it from the bog standard imp claw and to make it more, well, dark. Also, although ammo placement for souls as well the final effect for the Soulrender will have an impact on this, the heal beam alt-fire seems a bit powerful: It does hefty damage, hits almost instantly, rips through targets for multi-target scenarios and it heals you while doing it.
The Soulrender looks great so far, though the fact it fires the standard dark claw projectile at this point is rather amusing, given the enormous charge time.
On the subject of grenades, they take too long to throw at the moment. I would suggest having the player pull the pin as the grenade is raising rather than having it raise up and then pull the pin.