M3S - Fuse or Foe

Fuse or Foe is the last major mechanic of this fight, after which you will only see repeat mechanics up until you hit enrage. Once Brute Bomber casts Fuse or Foe, he will turn everyone into a bomb again while also firing a barrage of attacks that the party needs to dodge. Just like Final Fusedown, the party needs to resolve the bombs without accidentally hitting each other. However, the big difference here is that a strategy exists that fixes all the positions for this mechanic, essentially trivializing the whole sequence.

Wingwan strategy

The positions slightly differ from the regular clockspots for this specific mechanic. Notice how the healers and melee DPS have swapped positions in order to guarantee melee uptime.

The boss will randomly start on either north or south for his Infernal Spin. Regardless of whether the boss starts north, south or spins CW/CCW, the same movement ideas can be applied to all of them. Stack up behind the boss and in the opposite direction of where the boss is spinning towards.
The party should move in the same direction as the boss is spinning once the big AoE resolves. Now, wait until the donut resolves.
The donuts are gone now. Use this chance to cut through the center to the other side, allowing you to dodge the rest of the Infernal Spin. Your cue to get to your waymark positions is once the boss stops rotating.
The boss has stopped doing his rotation attack. Immediately get to your waymark positions and stay in it, using minimal movements to dodge the remaining telegraphed attacks. The role group with the short fuse will now resolve.
Shortly after, the long fuse group resolves while the boss is casting either Octuple Lariat or Quadruple Lariat.

After resolving either Octuple Lariat or Quadruple Lariat, the boss will follow this up with Brutal Impact.

Barbarous Barrage

This is the same knockback towers you saw at the beginning of the fight, but the difference here is that the boss will use a Lariat Combo instead. It is a repeat mechanic nonetheless that is combined with a normal mode mechanic, so dodge it as usual.

After dodging the lariat, the boss will cast his final mechanic before the enrage sequence, which is a Knuckle Sandwich. Whoever is intending to invuln this one has to provoke early, right around when the boss casts Barbarous Barrage. Otherwise, you can always soak it together with your cotank, especially if the party has a WAR.

Doping Draught

If the boss still has not been defeated at this point, then the boss will pop his Doping Draught again for the third and final time. This is followed up with Special Bombarian Special, which works exactly like the one in Doping Draught 2, except that the knockback is now unstopable and will send everyone into the lava pits. You have time until the boss jumps away to do his body slam, after which it is over and a wipe is imminent.