I prefer Himmelsdracheschwert (mostly because Lindwurm implies a ground-bound dragon of some sort, despite the wings), but eh, post #1794334 is just too good to pass up.
Plus it sounds nicer (especially from a chuuni PoV).
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Lindwurmschwert (Tenryūtō)Lit: Sky Dragon Sword. Or Tenryuu's Sword.