Deryl makes his weapons out of monster parts, if that's what you mean, but Xanthe also makes weapons out of monster parts. The massive guns that shoot pink plasma (used against you by Jake's goons) were created by Xanthe.
Even Xanthe's weapons are apparently ineffective against A-Class monsters, but Deryl's weapons were capable of harming a level 4 (generally level 4s are considered comparable to A-Class monsters).
I will say that it's a bit ambiguous because I'm pretty sure superhumans have much weaker bodies than monsters. Both Oscar and Kenny, who were heavily monsterfied, have extraordinarily powerful bodies. So it's possible that even Deryl's weapons wouldn't be very effective against an A-Class monster.
Furthermore, it's possible that the instructor has a different definition of 'effective'. I mean, even with Deryl's weapons it took an extraordinary amount of ammunition just to weaken Cole.
The way Deryl explains it, it's not really that ambiguous. I mean, it's still magic, but the mechanism seems to be well defined.
All monster weapons are powered by something. Xanthe's weapons have an energy core (rechargeable battery basically). Deryl's weapons do too but he can hook them up to his Philosopher Stone which is a multi-tool that acts both as the schematic and the battery.
So their difference is how much energy these weapons can pull from their battery at a time and how much energy this battery can hold.
Deryl's stone can hold more power than what he can output by himself and he has comparable power to MC. Against Cole, he ran out of power but his stone still had enough for MC to make good use out of it.
Xanthe's weapons on the other hand can be recharged by Tiffany, multiple times, and as a level 1 it's unlikely she has more than 15 Power.
Soldier "Damn, my
energy core has almost run dry. At this point
I'm just shooting normal bullets."
Herom "*pant* I'm running out of power too, there's so god damn many of them."
Herom "Miss Miliken, could you....?"
Tiffany "Got it."
You "Sounds like a lot of human weapons."
Deryl "Pshh, and your blades aren't? Humans know how to kill, probably better than anyone.
It's just power that gives monsters and shit the edge."
Deryl
"But with what I got these weapons hooked up to, power is not gonna be a problem."
From there on, I guess it depends on the design. These weapons probably have a limit at how much power they can draw at a time. So if he evolves, he may need better designs to make use of his expanded energy pool. Or instead of having 1 weapon on each shoulder, he can make a platform that carries 200 weapons instead and all of them will shoot at maximum for an extended period of time.
