I had an idea for a non-rare, -affiliated weapon, that I think would fit well with your martial training theme, so I'm just going to give it to you in hopes that you make it work. Brass Knuckles|Cestus does 1 to 3 damage (depending on balancing), low cast (0 to 2 ) and attack as per adrenaline if you have a mark.
There is already a time mark dependent weapon I made that is similar:
Wrist Blade | KataraIt gets an adrenaline like enhancement from martial training:
"Bluring speed: attack an extra 1 time per 3 trainings with your katara or wrist blade", 10% per training
Ironically, I was going to use brass knuckles for it originally, but I ended up going with a katara instead since it was actually a little easier to make the 3D model for.
If you want, I could make you artwork for your idea though.
I've found people don't seem to like making mark dependent abilities too powerful though (hence why all of the ones I proposed only get the standard +1 damage for matching mark)... maybe you could have it be an active ability instead?
E.g. "Weapon: Deals 2 damage. Add 1 if mark is
.
2 combo: attack multiple times."
What would be a good idea for the martial training effect for this weapon?