Whats the deal with reversing the ruins to defeat the smoke?

The instructions are not very clear and Ive tried several things and nothing seems to work.

Grandmalinda4

You have to find the 3 or 4 runes at the top in reverse order among the ones at the bottom.
For example if your runes were B F G
you find the G first, the F second and so on.

There is a meter at the top that starts to fill. Find the runes and throw the pitcher of potion ( in your inventory) at the Shade before it gets to the end. You do this several times (maybe 5 or 6 I forget) until he is defeated.

Good luck