Warning: this guide contains spoilers for the Mario RPG game.
Once you’ve finished the main story, you’ll be able to take on several of the key bosses a second time, with much harder forms.
Read on to find out how to unlock Super Mario RPG’s post-game boss rematches and tips for how to defeat them.
How to unlock Mario RPG’s post-game boss rematches
In order to unlock the secret second-phase boss rematches, you must first finish the game and access a Clear Data file.
Mario will wake up in his bed, and you’ll be gifted a free voucher for the honeymoon suite in Marrymore Inn. Stay the night, and Geno will spot a shooting star out of the window.
Next, you’ll need to head to Star Hill and find one of the new pink stars. Geno will then tell Mario to visit the Frog Sage to find out what to do next.
Head to the Tadpole Pond and speak to the Frog Sage. He’ll tell you to revisit the Belome Temple next to Monstro Town, where you’ll fight Belome again.
After defeating Belome, the Frog Sage will tell you to rematch other bosses in the game. Eventually, you’ll obtain the Super Shiny Stone and be able to unlock the game’s super secret boss, Culex 3D.
How to beat Punchinello’s Rematch
To beat Punchinello’s second phase, you’ll want to use Peach’s Sleepy Time move immediately whenever new bob-ombs spawn, putting them to sleep and giving you more time to deal with them.
For any bombs you miss, button mashing the A button when they move to self-destruct in front of you should always result in a block.
How to beat Booster’s Rematch
To beat Booster’s second form, you’ll want to start off by muting his minions with Peach, and terrifying them with Bowser.
Then, whenever he starts working, immediately disrupt him with an attack. Also, make sure you have revive items and party members in reserve should he wipe you out.
How to beat Bundt’s Rematch
When fighting this wedding cake boss’s second form, make sure you have plenty of Sleepy Bombs in your inventory, which are purchased from Tadpole Pond.
These will put the two chefs to sleep, allowing you to focus on defeating the cake itself.
How to beat Johnny Jones’s rematch
For Johnny Jones’s second fight, you’ll be unable to use party members or items.
Make sure you’ve acquired the Lazy Shell armour and equip it on Mario, as this will make the fight far easier. Then, it’s just a case of practising your blocks on Johnny’s various moves.
How to beat Culex 3D
Culex has the most HP of any boss in Mario RPG, if you include his four crystals. It also means he dishes out tons of magic attacks with each turn.
You’ll definitely want to prioritise Peach in your party, ideally equipped with the Lazy Shell Armor so she can stay alive, reviving allies and dishing out healing magic.
You’ll also want to make sure you always have somebody alive in reserve, and a full inventory of revive items, because in Culex’s second phase he has a magic attack that can wipe out your entire party if you’re unlucky.