Aw thanks! And it’s not spoilery at all.
He left several narcissus flowers as a calling card for Orpheus back in Chapter One. (He thinks humans are as clueless as he is.)

My headcanon is that Hades and Persephone were having happy special married time together in Nysa a year or two after the events in Destroyer of Light.
A bunch of flowers appeared afterward, and he assumed it was Persephone’s doing. That is until she started running through the flower filled field flipping out about them (and subsequently wove him a flower crown from them in her excitement).

At that point they discovered that he had gained some of her abilities and she his, and both of them set about idly practicing them for the next several decades.
Likely not going to write out that scene, but I won’t stop anyone if they wanted to.