In this encounter you fight four bosses in two pairs of two. You have to make use the buffs and debuffs you gain from one boss' abilities against the other. After you get them low enough, they combine to create Captain Pla... Elemental Monstrosity. The health of the Monstrosity depends on how evenly you damage the previous bosses.
Gpiano - Changes
Orjan Nilsen - So Long Radio (Jonas Stenberg Remix)