If you want an intro to this series, watch the anime or read the novel. They're so much better. There's a level of emotional nuance and delicacy that just isn't present in the manga version. I thought the production for the anime was beautiful, and had me tearing up with the season 1 finale. It just got greenlit for season 2.
The manga skips too many details.
(BL) mc reincarnates into the father of a villainess (an evil duke), and basically plots everyone's downfall, starting from the crown prince. Originally, stole the woman his rival loved, then later gaslights the rival into thinking he's a righteous person, then makes the rival fall in love with him too, then bangs him also.
Later their kids get together. There's also a dragon, and they reincarnate or something.
~ Now Kiss ~