Part 52

Phase 1: Minion Mayhem
Bowser has 75 HP. He will summon minions that you should ignore; focus solely on damaging Bowser. Recommended stickers include Thing stickers or Flashy/Shiny Shells and Flashy Fire/Ice Flowers. If you have the Thumbtack Thing sticker, use it early to pin the doors shut, preventing Bowser from summoning more minions.

Phase 2: Thwomp Trouble
Bowser has 225 HP. The main challenge is defeating the Thwomp. You have two options: use the Eekhammer to knock the Thwomp over and then attack with Scissors, or use a Flashy Infinijump sticker for 100 damage (the Thwomp has 50 HP). After defeating the Thwomp, focus on damaging Bowser without using your strongest stickers.

Phase 3: Lava Pit Peril
Bowser has 175 HP. The walls lower, creating a lava pit. Bowser will heal himself. The primary threat is lava bubbles. Use the A/C, Shaved Ice, or Refrigerator stickers to freeze them. If you have the Fan sticker, you can blow away the frozen bubbles. If the lava melts (it stays frozen for three turns), its attack deals 16 HP damage. Focus on damaging Bowser quickly.

Phase 4: Molten Edge Maneuver
This phase is easiest with the Shiny Tail Thing sticker. Use it, and have the Chomp hit you. The Tail will cause the Chomp to push Bowser over the edge, instantly proceeding to the final phase. If you don't have the Tail, you'll need to rely on Slaphammers.

Phase 5: Kersti's Return
Initially, focus on healing and surviving Bowser's attacks, which deal damage. Press A just before his slap attack hits to halve the damage. Once Kersti joins your party, use her abilities. Attacks will only deal 1 HP damage until Kersti joins.