Infernals
Infernals originally weren't going to be part of Exalted vs World of Darkness for a number of reasons, and indeed weren't included in its initial release. I very emphatically didn't want to drag the Yozis back into the picture, since they're long dead or fragmented or otherwise irrelevant. I also didn't want to make them into speculative stabs at what Third Edition Infernals might be or could have been.
Later, though, I kept thinking about them, and what it might be like to include them, because people like them, and I like them. In the end, I finally figured out a way to do Infernals that feels true to their core themes and concepts, suits the World of Darkness, and calls back to some of their more fun and memorable elements without running afoul of any of the stuff detailed above. They're weird, they're Hellish, they don't quite
work like anything else, and they're rooted very much in the mythology of the setting: that's Infernals, to me. In their original conception, since they didn't have Castes and thus didn't have anima powers, it fell to Shintai forms to take up a fair bit of slack.
When Solars and Abyssals got Supernal/Apocalyptic Charms, Infernals felt like they fell behind a bit, and got Crowns to catch them back up. Shintai forms are extremely powerful but also of extremely limited use in part because "Behold my true form and despair!" rapidly loses its flash if it happens every session, and in part because I didn't want them to just be Solar-Charm-power-level Exalts with a Lunar rage form dropped on top. Tonally, they're supposed to contrast the cold, glorious, chilling menace of Abyssals by being brash, vulgar, and brutal: Alucard from Symphony of the Night vs Alucard from Hellsing.