For the Fighting the Windmills achievement, since you need to deal little damage while surviving extreme amounts of per-turn damage from Big the Jonathan, the Guardian and Supporter roles as well as defensive and healing cards are strongly recommended. A team of 4 Kyokos using the Guardian role can reduce his damage extremely well.
If Dive is cancelled via Banned for Life or Melting Memories, the boss will skip diving this turn but instead dive next turn, however, there will be no preview that the card will be played. The red tint marks the panel where it will dive also disappear, and the range of effect will no longer be boss panel for that turn (unless a Terror event is happening).