Can we get some uhh Stalliod headcannons 👀
They first met in old Marleybone, back when it was part of greater Avalon and hadn't split off into its own world (personal headcanon. Long story short, worlds suffer continental drift). Time-wise, this was pre-Schism
The Old One was more reserved in whatever relationship they had. He knew he couldn't reveal all the layers of truth to Stallion, a nonmagical man. All the worries of the end-times, how he (a single man) wanted to play god to save his favored parts of the Spiral
Stallion was more open from the get-go. He was a man of discovery, of finding secrets and the truth! Having his own secrets seemed hypocritical to him. He wanted to know everything about the Old One as much as he wants to one-day explore the vast universe that SURELY existed outside of Avalon.
Stallion Quartermane is one of the only people the Old One trusts enough to give his True Name to. You know, the Name that lets wizards summon the beasts and beings in their spells? Speaks volumes abt how I interpret Stalliold tbh. Not enough trust to share a name that Stallion can speak and put within his journal, but enough trust to share a name that would summon him at will. (yes I know Stallion Quartermane as a boss cannot cast Old One's Endgame but canon can be stretched and ignored for the sake of absolute disaster gays)
Stallion gave his True Name to the Old One as well. It's only right to reciprocate such an act of trust.
That necklace Stallion wears? A gift from the Old One. Stallion cherished it because while (at some point deep in their relationship) Stallion knew that the Old One loved and cherished him, he hardly ever showed it beyond flowery words, funding his expeditions, and sharing his True Name. The giving of the necklace was an action, in Stallion's eyes. A true symbol of "I love you, and you alone. I got this for you, and you alone."
By the time the betrayal in Madness Mountain occurs, Stallion had been wearing the necklace for so long that he doesn't even THINK to take it off. Though the meaning is broken, the literal weight of the necklace has become so natural to him that taking it off feels physically wrong.
Also, @wizzycore had a LOT of thoughts about Stalliold in the discord server that I think you might enjoy (don't worry, im sharing these with their permission):
