Xenoblade Chronicles Guide- Walkthrough Part 71: Mecha-Calamari

As Shulk leads the assault on the Mechon that has captured Juju, the Monado guides him-

Monado Flash!- As Shulk charges, a tentacle erupts from the ground ahead of him, blocking his way.  As he shifts aside to go around it, two others loop around to intercede- one strikes from his right, misses, curls around, and belches a flaming rocket out at the swordsman.

Returned to reality, Shulk stops short and severs the first tentacle as it erupts with a horizontal cut.  Evading the second strike, he smashes the tentacle with the Monado’s blade, then rolls backwards and away before the rocket even launches, using the blast to leap back and come down with a slash that severs a third tentacle a short distance behind its pincer.  Reyn then darts in, sidestepping three tentacles one after the other without even seeming to try.  Sharla runs into view here, juking left as a tentacle tries to strike her head on, then turns and opens fire on it with her rifle even as it passes behind her.  Another pincer lashes out at her, but even as she sidesteps, Reyn gets in the way, smacking it aside with the barrier on his Driver.

Only slightly out of breath, Sharla regroups with Shulk, praising his ability to enhance his allies.  Shulk declines the praise, claiming the power is entirely from the Monado as Reyn joins the others.  Reyn agrees with Shulk’s assessment, pointing out the blue glows that now swirl around the three as being purely the Monado at work.  He then urges the others to get on with fighting the tentacled Mechon.

This fight is fairly simple- lower-level characters will need to keep moving so that they aren’t assaulted by the flaming rockets and erupting strikes that the tentacles of the mechon dish out, but those at a higher level needn’t worry- this thing is only level 17, and the tentacles are level 15.  This is made all the easier by Shulk’s access to a new Monado Art: Speed, which does as it suggests and boosts the movement speed and dodge chances of all party members.  Killing off everything is a bit of a chore, but all you really need to do is focus on the main core of the Mechon.  Once this is down to about 2/3 health, the fight cuts off.

With the three heroes regrouped yet again, Reyn asks if the Mechon is finished.  It seems so for a moment, as the thing has all its limbs pulled in, but it abruptly shifts, grabbing onto the ceiling and clambering up to the top of the higher platform.  Reyn sounds annoyed by this, but Shulk just directs the others to chase the thing up the spiral ramp.

The second part of the fight is much the same as the first, but the Mechon is in a defensive mode now, and is much harder to injure.  Still, characters of high enough level have nothing to really worry about, and whatever you do, you should focus on cutting down the main body of the strange machine.  The main danger here is not the power of the attacks, but the sheer number- the thing has all eight tentacles active and is constantly lashing out with the lot of them.  You can use the Arts available to your party members to stave off a lot of the damage, and this is a good time to hit the main body of the thing with a Chain Attack, a long enough one will take out the majority of its remaining health without much trouble.