had a realization just now about Familiar of Zero, aka, a fan-favorite series for crossover nonsense to happen in. It’s got the perfect setup for serious fics, crack fics, romance fics, you name it, you can literally throw any other character into Saito’s role and make wild shit happen.

That said.

The premise of the series hinges on the character in question not immediately going “fuck this, lol” and bailing on the ritual. Once it’s completed you can generally finagle a situation in which they stick around even when Louise is being... well, start-of-the-series-Louise, just by handwaving it as a subconscious compulsion from the Gandalfyr runes. However, there’s still a minute-ish long gap between the character being summoned and Louise completing the ritual with a binding kiss.

Which means some of the characters who’d make for absolutely fantastic disasters in Halkegenia likely aren’t going to let that actually happen.

For example, if you want to summon Kakashi Hatake into halkegenia, there’s three realistic outcomes. He either instantly vanishes and starts doing reconnaissance, he comes out swinging, or he fucks off to go find someone who knows enough to fix this. In none of these situations, is he going to allow this random teenage girl to kiss him, because he’s ten years her senior and does not need this right now. (Any of the akatsuki are in the same boat, except most likely “comes out swinging” are plans A through Z)