Maron (he has no last name but keeps trying to claim Kiyo as his surname as proof of his commitment to his serpent) was found three quarters of the way to dead by Il'kiyo in the lower levels of a dungeon. The harm came not from monsters but from men, his group caught up in bacchus madness and hacked at their Swordmaster, overwhelming him as he refused to attack back.
Nursed back to health and attempting to send him on his way, Il'kiyo ended up witnessing Maron swear fealty to him, vowing to be his sword until the end of time (he didn't know at the time that Il was in fact, a truly gigantic flying serpent but the thought was there). Amused by the human knelt at his feet and sounding like he was proposing marriage, the Icebound offered him a blessing and accepted his contract.
While the Dread Wind has no need for a protector or a bodyguard, he does have need for a formidable fighter to go out and hunt down ingredients needed for commissions when Il can't get away from the shop himself (usually because Yah is missing)
The Blessing joins the pair of them together so that Maron is a little sturdier than even the toughest of baseline humans. Senses enhanced, stronger, faster, capable of healing quicker, but he is still very much mortal and can die from all the things (pretty much everything) that can kill a human. He can use it to call on Il'kiyo if he's in serious danger and it allows him a tiny fraction of the serpent's magic (though he can only use ice with any true skill)
Very much in love with Il'kiyo but it's very much one-sided.
Yah teases him about it constantly outside of Il'kiyo's earshot.