Clair Obscur: Expedition 33 – All Act 3 optional bosses and where to find them

When you get into Act 3 for Clair Obscur: Expedition 33, you’ll be given free rein of the open world, and a lot of new areas, activities, and boss fights will be open to you. There are loads of places to check out, but the game doesn’t do the best job of tracking where you’ve already been or reminding you of what strong enemies you need to go back and defeat.

We’ll break down all of the major bosses available in Act 3 that unlock achievements/trophies when you defeat them, explaining where they are, how to defeat them, and what you get for doing so.

Sprong

Sprong is likely the first of these tough bosses you will have encountered as he stands partially submerged in the ocean just north of the Endless Tower. He’s also the first one you’ll want to defeat, as the reward you get for defeating him will make everything else much easier.

Sprong has a lot of health, but it has a predictable attack pattern with strikes that are pretty easy to counter – at least by the late-game standards of Expedition 33. As long as you can withstand and counter its strongest attacks, then you shouldn’t have any trouble defeating it.

Defeating it earns you the “Sprong” achievement and the Cheater Pictos, which allows equipped characters to act twice in a row on their turn. It’s easily one of the best Pictos in Expedition 33, and it’ll help you defeat all the other bosses on this list.

Grosse Tete

Grosse Tete is a bit of a pain, but one you can theoretically defeat quite early if you’re good enough at parrying. You can find it east of the big island with the snowy area, on a smaller island with orange trees.

It is very resistant to damage, but thankfully, you don’t actually need to empty its health bar to kill it because it’ll do that for you. Each time Grosse Tete attacks, it’ll add two more bounces to its combo. After its twelfth attack – in which it will bounce 24 times – it will explode and you’ll win the fight.

This one doesn’t come with an achievement, but you do get the Warming Up Pictos, which increases your damage by 5% every turn five times.

Serpenphare

This one is hard to miss as it’s a glowing snake monster floating in the sky. It floats near the Boat Graveyard area, so just fly into it to encounter it.

Serpenphare attacks quickly with both its head and tail, but these aren’t the biggest challenge when fighting it. The major challenge is that it stacks a lot of shields onto itself every time it attacks, meaning you need either Maelle’s skill that absorbs shields or one of Verso’s or Monoco’s skills that deal damage through shields to deal with it.

Beating it gets you the “Á On” achievement and the Energy Master Pictos that increases AP gain from any source by one.

Clea

Now we enter the territory of what can be reasonably described as a superboss, as Clea is extremely tough.

Floating above the southwestern edge of the big snowy island, you’ll find a series of rocks in the sky, and the center will be a broken manor with a portal to the Flying Manor area. In there, you must defeat tougher versions of four bosses from earlier in the game to unlock the manor door. Head inside and you’ll discover the painted version of Clea, Alicia and Verso’s sister, who was so powerful she painted over herself in rebellion against her mother.

Clea will unleash waves of other painted monsters to attack you, and you need to be absolutely perfect with your parries here because if you don’t counter her attacks, she will heal over 500,000 HP every single turn. You either need to make a speed-focused party that can outpace the rate at which she heals or parry every single strike perfectly to stop her from healing.

You’ll get the “Clea” achievement for defeating her and Clea’s Life Picto, which fully heals characters if they haven’t taken damage since their last turn, and yes, it stacks with Cheater.

Simon

Simon is the superboss to end all superbosses. He is by far the toughest fight in the entire game, so don’t even think about approaching him until you’re Level 90 or higher.

You’ll find him in an area called The Abyss, which can only be accessed through Renoir’s Drafts. To get there, you’ll need to have completed Esquie’s bond side quests and unlocked his ability to dive underwater. You’ll then be able to enter Renoir’s Drafts at the portal in the ocean between Visages and Siréne.

Simon is a three-phase boss fight with some outright unfair abilities, which include absorbing the health of your party – keeping them constantly at 1HP – and if any of them fall in battle during Simon’s turn, he will erase them from the battlefield so you can’t revive them. It will test your mastery of every battle mechanic in the game. We recommend a speed-focused set that builds to a 3/3 Gradient Charge as soon as possible so Maelle can one-shot Simon with her Gommage Gradient Attack.

Doing so will earn you the “Peace At Last” achievement and the weapon Simoso, usable only by Verso, that makes him immortal provided he is at Perfection Rank A or better.