Sure I can! Thank you for the question!!!
Ichisan - wet & messy, if Sanji isn’t soaked enough to water plants for a week Ichiji hasn’t done a good enough job. Because of this I like to think Ichiji is heavily into watersports the control aspect of forcing Sanji to piss himself but also is just an easier way of making Sanji wet without Ichiji having to finger blast him for 30 mins, also think there’s some small part of Ichiji that likes to be dirtied he’s the next king of Germa and here he is getting pissed on and getting all dirty. Also Ichiji prefers to creampie Sanji watch his cum drip out and then spread his seed all over Sanji’s hole AND THEN push his cock back in like I said he’s messy :) I also HC that before Sanji came along Ichiji kind of viewed sex as unnecessary and kind of bothersome?? lol everytime he got horny he’d be angry that work is being disrupted also I think he’s too much of a sadist to really enjoy normal sex and every time he does try to indulge with normal women they’ve always ended up super injured enough so that Ichiji does end up getting scolded for it 😭 but Sanji’s a lot stronger and also Germa doesn’t care if he gets badly injured so win win for Ichiji. After Sanji does join I imagine Ichiji turns into a massive sex pest lmfao even with meetings that don’t involve Sanji you bet Ichiji’s dragging him along just so Sanji can suck him off underneath the table. Also drags sex wayyyyyy out for him and Sanji, Sanji’s cumming at least four times before Ichiji even thinks about putting his cock in Sanji. Depending on what im writing/feeling I think Ichiji is actually more into Sanji being reciprocated to the sex then Ichiji just forcing himself onto Sanji sure he can rape Sanji whenever he wants but where’s the fun in that? Ichiji always gets what he wants and he likes a little challenge from time to time! Again like I said entirely depends I do like it when Ichiji rapes Sanji in fics I’m honestly not picky. Really likes it when Sanji calls him king or master not a big fan of being called daddy probably. Also a big planner hates spontaneity prefers to set out the time him and Sanji copulate because once he starts he’s not stopping no matter what however if Sanji comes to him hole full of cum begging to be filled again well Ichiji certainly isn’t going to say no.

While I do think Niji is a sadist I don’t think he’s that kinky? Like he has his fetishes like biting, scratching just making Sanji bleed and choking too, but I don’t think he’s into any elaborate ones he’s way too lazy for that in my head, he literally just wants his dick wet and to orgasm. I do think if he gets overstimmed a little too much his lightening powers get brought into the mix which would be interesting lmao 😭 also I have this wip that is to do with Niji bottoming cause I believe he’s somewhat of a curious boy and would want to know if it feels good or not (if Sanji out of all people can find it good then Niji will not be outdone) he’s terrible so if you say no chances are he will actually be more turned out doesn’t care that it’s inappropriate or not the time his dick is hard and he expects to orgasm within the hour also likes an audience too so he’s more likely to fuck when there’s other people around (expect from judge) definitely prefers positions that have Sanji on his front so he can have his ass raised up in the air (also shove Sanji down into the pillow same kinda goes for Ichiji but he likes seeing Sanji’s expressions)
sorry this isn’t as long as Ichiji’s lol Niji is quite simple compared to Ichiji when it comes to sex