So you’ve reached the end of Solar Ash. You’ve overcome other bosses like the Burning Hunter and the Withered Eye. You’ve upgraded your health and gotten all buffed for the final fight. Now it’s time for one last challenge. It’s also time for spoilers, so consider this your spoiler warning. The strategy for the final boss can be found after the screenshot below.
You might have been expecting to fight the mysterious Echo at this point, but that’s not the case. Instead, you’re controlling Echo yourself, and you have to take down Wretched Rei, the corrupted form of our protagonist up to this point. Despite the twist, the pattern here is very similar to previous boss battles.
First, you need to actually climb onto Rei’s body. She’ll attack you with a trio of tentacles, so look for the targets on the ground to avoid damage. Once they’ve been slammed down, you can grapple onto one and grind up to Rei’s body, slashing at weak points along the rail. From there, destroy each successive weak point on her body until you get to the final grapple point — instead of plunging your weapon into Rei, you’ll be pulling debris out of her body.
As with other bosses, this fight spans three rounds. Tentacles are severed between each one, so dodging them is technically easier each time. However, the platforms on Rei’s body also shift, so avoid falling into the goop during round two or you’ll get stuck. Touching it when it’s heated in round three results in death and a restart of the round.
This is an important fight for the game’s narrative, but it’s not any harder than fights you’ve won up to this point. Keep going until you’ve nailed every weak point, and you’ll bring Rei back from the brink and finish Solar Ash.