Here the some info on this I found useful from another site.
Quote:
"As long as you have rank 1 of your progressive spell/ability memorized, it looks like Duality of Life and Duality of Decay both do the same thing as saying "remember" to the spell vendor in Tranquility, Warlowe Rida -- whether you click one of your items, or you talk to Warlowe, your progressive spell level is raised to match your current progression.

For example, I waited until I had group progression done through Decay, then talked to Warlowe, and she bumped my progressive spell rank from 1 to 3 without having to click either of my Duality clickies. So I guess I can destroy my two clickies. On another character, I clicked Duality of Life, and that also bumped my progressive spell rank from 1 straight to 3. Duality of Life was expended, and I have Duality of Decay left over which I assume I can just destroy.

You say, 'remember'
Your Spell Book has been updated!
Spell __#__ replaced at __yourname__ Spell Book at slot __#__
You have learned the third rank of your progressive ability! " End Quote

Questions? Comments? Post them here! Original page - https://items.eqresource.com/items.php?id=99833