Another One Has Gone Mad

The strongest skill in this world is my mother tongue. But... I've almost forgotten it. The strongest man in this world is my beloved. But... he died thousands of years ago. No angst over love, just a delightfully happy ending. A work written to make readers cry: a pitiful bottom and a weepy top (crossed out), actually a power couple. The giants in this story are based on mythology and have absolutely nothing to do with Attack on Titan, so please take note. The official pairing is the black dragon Nidhogg. No switching, no breaking them up.