Had a strange glitch and not sure if it's just me. After Felicity took me to drink together, I couldn't progress until I left-clicked. Usually use Space so ended up trying with different dialogue options until I realized what I needed to do.
Edit: Realized the problem. Been a bit of a long day so didn't click that I could interact with the environment.
Yes, got him to level 20 via dodge tanking for thousands of turns. Used him as a dodge tank for Chapter 2 to safely bait enemies into my range. Promoted him on Chapter 3 and just let him fight everything he could reach, and just let him deal with the fliers in Chapter 5. Then I did his event Chapter 6.
I was understandably terrified that I wouldn't be able to beat the last chapter of this version.