Bodyguard.
With Yu Liang's unique bloodshed combat style, they could strip the charms and items off an enemy player fully, even seal their badge, all at the cost of an arm.
The cost is indeed there, but a severed arm is but a small price to pay for such a terrifying benefit, isn't it?
It's not as if healing is prohibited. He could use healing charms or badges to recover later or find some adventurer's sticky clay to assemble a prosthetic limb.
In any case, there's a full status recovery after each instance. A few injuries during the instance are insignificant, as long as he's not dead.
Climbers, boxing trainers, marathoners, and basketball players, these professions might be unique and powerful in their respective areas, but none of them are as intriguing as the bodyguard profession.
Paired with Yu Liang's hidden feature "Opulent", it is a formidable weapon against others.