I had a hunch, a tingle if you will, when reading the earlier chapters. This TCG arc is some business ad, marketing shenanigans from college! THIS MANGA IS AN INDERECT BUSINESS AD CURICULLUM!
Girl has built-in shining finger. She'd probably be out there shouting here super moves on mountains and monster like "Demolition Finger!" and do literal ToDs on dragons and shit.
She's going full Snake now. She's the solid to the heroine's liquid. And the prince is Ocelotte, giving Princess Snake a kiss and saying she's Pretty Good.
Duke is doing the thing Ocelot did to himself to make himself believe that he's possessed by Liquid, but it was all just a ploy to have a one-on-one with Snake and kiss him and let him know that he's pretty good.
The "villain" side seems to have a lot of likeable characters while the "hero" side is a bit mixed. The saintess seems sketchy, the fiance is a mess, the King's a pretty reasonable lad, the prince is an absolute (ey) prick, and the hero is the shining example of a nob head.
How's the web novel...