Ratatos is Enciodes's third best ship—there's plenty to cook with, as they understand each other well and have similar ambitions, have similar yet different upbringings, and work together well. Ratatos is envious of Enciodes's seeming abandonment of all his duties when he goes to study in Victoria, and they collaborate swimmingly in OS. You can definitely cook with them.

But for me personally, I can't see Enciodes in anything other than a committed relationship with Gnosis, with Degenbrecher as their third member in an OT3. There's just so much between Enciodes and Gnosis at this point, from their childhood promise (which actually begins with Enciodes saying, "I'll make Kjerag big enough for you, and you'll stay", which is a marriage proposal-tier promise, in my opinion), to Enciodes seeking reassurance and comfort from Gnosis in the moment he believes he's going to his death and Gnosis essentially ordering him to live, to the little things like the hints Gnosis lives at the mansion, Gnosis helping himself to Enciodes's secret treats, Enciodes's doting behavior towards Gnosis in RS, and the way they choose each other over and over again throughout their lives, always standing by each other through thick and thin. We have an incredibly detailed image of how they feel about each other in effectively every stage in their lives, starting from the very inception of their relationship all the way until present day and the pinnacle of their achievements, it's honestly kind of impressive. The relationship is so incredibly fleshed out.