While Super Mario RPG is designed as a simpler, beginner-friendly RPG, that doesn’t mean it’s easy. Some of the late-game bosses are very difficult to topple to the point of being absolute nightmares. Culex isn’t even a mandatory boss, it’s an optional secret encounter. But you’re curious, so how do you beat Culex?
First, if you’re wondering how to even get to the Culex encounter, you can learn about it with this guide here. But now that you’ve found it, the hard part begins.
Preparation
I’d recommend not taking on Culex until you have the Lazy Shell (armor and weapon). To learn how to get them, this guide here gets you covered. This means not taking on Culex until after the events of Nimbus Land. The larger strategy here is still applicable if you want to take them down earlier, but it’s going to be tough to withstand their attacks without the Lazy Shell.
With the Lazy Shell, I recommend equipping Mario with the weapon. That’s kind of obvious; it’s the most powerful weapon in the game. For the Lazy Shell armor, give it to Peach. She’s the linchpin. Most of her special attacks deal with keeping your party healed, so if you put her in the nigh-invulnerable armor of the Lazy Shell, she can focus on reviving and healing the party. The third party member is a wild card. I’d recommend not using Mallow, since his AOE attacks have elemental properties that the crystals supporting Culex can resist. Geno or Bowser, however, it’s your pick.
Finally, load up on Rock Candy. You can get these by stuffing the face of the Toad in Seaside Town. They’ll munch on mushrooms and, every so often, will reward you with a Rock Candy. More information about that here.
Rock Candy does 200 damage to all enemies, regardless of the target, attacker, or resistances in play. It may not seem like a lot at this stage of the game, but it’s consistent, significant damage, and the crystals have high defense, so this negates them. Since Peach won’t have high attack capabilities because of the Lazy Shell armor, she should use Rock Candies whenever she has a spare turn. Note that you can only have three Rock Candy in your inventory. Freebies can help keep Peach attacking, but even without them, it’s a good trick to have.
The Fight
Culex comes out swinging, flanked by four crystals representing Earth, Fire, Water, and Wind. They each have different stats and attacks. You will want to target them first. So long as they’re alive, Culex will have five attacks per round, which will result in excessive damage. Until you can reduce the crystal population, Peach will have her hands full resurrecting party members.
Note that the Water and Wind crystals (Blue and Green) have the lowest HP. They also have high defense, but if you focus on them, they’ll pop the quickest. Earth (Yellow) has the highest HP and the lowest defense.
If you need more reason to target Wind (Green) first, it has the Petal Blast spell that turns everyone hit into mushrooms that are unable to attack. Peach should be safe in the Lazy Shell, but you may want to equip other party members with badges that negate such transformations. Otherwise, you can just have Peach use Group Hug whenever someone gets fungi-fied to change them back. Take Wind out quickly to stop the transformations.
You don’t have to take out all the crystals to defeat Culex. Earth has about three-quarters of Culex’s overall HP, and even with its lower defense, it might be quicker just to ignore it and take out the main boss. It’s up to you. On its own, Culex’s attacks aren’t that impressive, and they will often use Shredder instead of something that causes damage, so once you knock out all the crystals, the battle is essentially won.
As for the rematch
At the end of the post-game rematches, you’ll get the Extra-Shiny Stone and be able to challenge Culex to round 2.
This battle is similar to the first fight but with one major difference. Culex will come out with an attack that always hits for a party member’s health, minus 1. So, if your party member is at full health, they’ll be knocked down to 1 HP. If they so much as have a scratch on them, they’ll get knocked out. He’ll then start a timer that ticks down to when he’ll do it again. Once more, the linchpin here is Peach. She can keep the party topped up before and after each of Culex’s big swings. If you don’t think you’ll make it to her turn, you can instead use a Croaka Cola to fully recover.
Then, once all the crystals are taken out, Culex’s big attack becomes a one-hit KO on a single party member. This is actually better, since it won’t potentially take down your whole party at once. You can also block it to prevent damage. Even if you are perfect with blocking, it’s still a difficult fight. Culex has incredible piles of HP that you need to hack through. Thankfully, if you survive this fight, you’ve bested the best that Super Mario RPG has to offer.
