Hisirdoux is not much a melee fighter– not that Merlin has yet allowed him many lessons on combative magic yet, anyway– but he did grow up on the streets. He looked harmless, but he had been forced to defend himself more than a few times. As such, he doesn’t own many weapons, nor quality ones at that, but he does have a small knife he’d swiped from a passing palace guard– he was quite sure the man had plenty of access to replacements. Hisirdoux wouldn’t claim to be a warrior by any measure, but if he had to, he could hold his own. Usually, he also had Archie’s help, so generally, his need to fight another person was tempered by his own familiar’s help.
It’s Morgana who notices that Hisirdoux carries the knife in a sheath on his belt, hidden from plain view by one of the packs attached at his hip.
It is also Morgana who asks him if he knows how to use it.
In an anxious, ramble-y way, he roundabout gets to his answer, which boils down to: yes, but no. (He was still new to everything, and could barely believe that Morgana was even talking to him, much less trying to learn something about him).
Morgana offers to train him, then. Of course, first he needs a proper dagger. She almost throws out his knife, as it is considerably dulled, but he saves it before she does, unable to part with it. It is a rare physical possession of his that he procured on his own. (He is still afraid that if he gets sent away again, he will lose whatever possessions have been given him in his stay at the castle).
Still, she makes him practice with the good dagger that she’s given him, and while it’s a touch different than some dull, glorified kitchen knife, he is able to adapt what he’d been doing on instinct into actual technique. He is not exactly planning on becoming a master melee combatant, but he can hold his own, and Morgana does not fear his competency with blades any longer.
When he gets far enough in his lessons with the dagger, she begins teaching him staff tricks sans magic, but those are even more secret than the secret dagger training, because Merlin would kill her if he found out. She just thinks it’s sweet how excited he is at someday getting his own staff.