Item description:

Follow the linear path to the top of the Tower

Go right and look at the big stone
(A ? will show, press X)

Go left and look at the portal to the Ether Bridge
(A ? will show, press X)

Walk right and Bonku will appear

When you have control again, run right and pick up the Arca

Choose your ending
(Go left to the Ether Bridge or go right to the Crystal and pres X)

!! Let the credits roll !!

** Mostly all dialogue, so it's a little long
Press O twice (will have 2 arrows) to skip dialogue quicker **