Big the Jonathan (ビッグ・ザ・ジョナサン Biggu za Jonasan) is a special super-powered boss only found in Co-op Mode. It was originally introduced during the Beach Party event in 2018, before Co-op as a mode was formally introduced with the Minions of the Master event. It was later added as a permanent Co-op boss in the Beach Party rerun event.
- When a player suffers KO, gain +1 ATK for 1 Chapter.
- At the start of every 10th Chapter, gain permanent +1 ATK, -1 DEF, and -1 EVD.
- (Unlisted) Use on Chapter 50.
- (Unlisted) If the game is not over by the end of Chapter 50, Big the Jonathan will lose the game.
- (Below Hyper Difficulty) Every 4 chapters, use at the end of Boss turn.
- (Hyper Difficulty) Every 3 chapters, use at the end of Boss turn.
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.
- During Launch, the boss is unable to be targeted by Boost cards (such as ).
- If Dive is cancelled via or , 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).
- Dive will convert panel into panel.