I'm back with more ideas! Also I hope I'm not being a pest with this....
Luminous visits Veldora to make sure he's okay but to basically take advantage of the fact he's sealed to tease the crap out of him using whatever clothing she could get her hands on. (Cause this is Luminous Valentine we're talking about and we all know she'd do this in the name of messing with her husband) In fact, one of the main reasons why he takes uses his dragon form more is because it doesn't (physically) have a reaction to her teasing. He tries to get her to be careful in case a random adventurer pops in or his sisters suddenly remembered they had a brother and decided to visit. Which they never do to his disappointment and Luminous's rising anger. It also solidifies Luminous's hostility towards the two, more to Velzard than Velgrynd.
Also, is it okay if you make them a bit stronger than in cannon them since, let's face it, the partners of the True Dragons are absolute monsters out of all of their kind and there's no way Luminous would let herself lose to them when it comes to that. She also has Asmodeus for obvious reasons (Veldora dying to his Velzard who kills him despite him no longer rampaging much for stupid reasons. The pain of feeling him die via Soul Corridor. Waiting YEARS for him to regain his lost memories etc) even though it really doesn't work on him, to her despair but Veldora promised he wouldn't die much which he kept till his sealing.
Veldora also is more of a dad to Rimuru than a brother in comparison to cannon since unlike his counterpart, he actually WANTED to have kids and TRIED with Luminous (even bought and made clothes and toys for the baby) but the constant failures hurt until Rimuru existed and he focused in being a dad to him.
