Honestly? A lot of crossovers feel like they're just slapping a popular character into Lordran for the cool factor, which gets old fast. The pairings that actually work dig into the fundamental misery and cyclical decay of that world. 'NieR:Automata' and Dark Souls is my hill to die on. Androids built to fight a never-ending war for a long-dead humanity landing in a world where the fire is fading and the gods are gone? The androids' search for meaning in a pointless conflict mirrors the Undead's hollowing perfectly. 2B and 9S trying to apply logic to the nonsensical curses and timelines of Lordran creates this brilliant, tragic friction. It’s less about who can beat up Ornstein and more about how their core philosophies shatter against the setting.
Another one that doesn't get enough love is crossing it with something like 'The Locked Tomb' series. The deep, gothic, and utterly bizarre necromantic magic of the Nine Houses crashing into the First Flame's age of fire? The aesthetic overlap is already there—cathedrals, skeletons, deep lore. Harrowhark Nonagesimus trying to parse the miracle of Estus or the nature of bonfire resurrection through her bone-obsessed lens would be a character study in itself. The tone just meshes in a way a more straightforward fantasy crossover often fails to do. It’s about matching the profound, almost existential weirdness, not just the swords and sorcery.
Archive of Our Own has become the central hub for the majority of 'Dark Souls' crossover work I've encountered. The tagging system is genuinely a lifesaver for such a specific niche—you can filter for the exact 'Souls' game and the other fandom you want, whether it's 'Elder Scrolls' or 'Berserk'. I've noticed a real concentration of long-form, plot-heavy stories there that treat the bleak worldbuilding with the right kind of grim respect.
Some older platforms like FanFiction.net still hold a surprising number of these crossovers, but the search function is a nightmare. You have to wade through a lot of generic 'Chosen Undead gets Isekai'd' premises to find the ones where the author actually understands both source materials. The quality can be wildly inconsistent, but I found a few gems years ago that I still reread, stories where the mechanics of hollowing are explored through another universe's lens.
Honestly, the best stuff sometimes feels scattered. I've stumbled upon fantastic 'Dark Souls'/'Bloodborne' fusion pieces tucked away in smaller forums or personal blogs, often linked from subreddits like r/darksouls or specific fanfiction recommendation threads. It feels more like a communal dig than a straightforward browse.