Hello! Thank you so much and we're happy you liked the game so well! Thank you for your support! ;D
The characters are all very special to us so we took our time to develop and bring them into the story! So we're super glad you liked the side characters too! >w<
As for your question, yes, there will be a guide! It contains both a general stats check overview and a detailed ending guide if you guys want to follow that instead XD For the early access peeps, we will release a short overview as an extra file to this game, to thank you guys for the support!
Everything else + artbook + character information will be released separately, but we will post that in an extra announcement!
The stats bonus from the daily death will only apply to the MC! As in... you get stronger if you die, but the princes won't gain anything from your deaths XD
Each of the princes have their own preferences! Although they sometimes mix them up with other things :D These will be pointed out in the guide too!