I got a second Levin and I'm still kind of unsure a out how to make the most out of SS. The only ones that come to mind are my Libra and Charlotte, but both have Wrath (which seems better)...
Then don't fodder. Unless you have another unit that you adore as much as Libra/Charlotte/Henry, or you want to experiment, then there's really no reason to fodder him for Special Spiral.
Just wait for when we get another unit to FEH that you like to think about foddering. Who knows, maybe the new Fates banner will have someone that you like, like a regular Charlotte.
Ranged Infantry come to mind since they don't have access to Wrath. However, a lot of them really appreciate Desperation for B-slot. Maybe Lilina since with Forblaze her role is nuke with middling speed? But I have no idea if that would actually be that great an idea but it's an idea that popped into my head.
This might just be me, but SS on a high defense/res hero helps so they fire off Ignis and Glacies consistently. You sacrifice QR or Guard which most people prefer on that type of unit and l haven't tried it myself since don't have access to SS, but just wanted to throw the thought out there.
Pokemon GO
Fire Emblem Heroes
Fate Grand Order
Dragonball Legends
Dragalia Lost
IV Calc
Heroes