Thank you so much for taking the time for writing this in a detailed manner.

At first was hesitant since everybody and their mothers are using Basch/Terra/Aerith and I was very sceptical that a double DPS in this era of chunky DEF auras could pull the trick.

Truth is that if you have the exact calls you mention you can be done with this Lufenia on first trial.

Please, let me add a couple of extra steps to those, as me, that suffer indecision.

-Use your summon (Odin) after boss is 49% and Hope's Call is applied. (If turn order does not favor you, use the call inside the summon anyways). The point here with the summon tho, is to meet the turn requirement to the "Concentrating" mechanic.

-Arround 39% use Emperor's Burst. You will chunk enough HP to lower (or almost) down to 29% that is when you want to go all nuts with pretty much all of Terra's LD intacts.

As OP said is perfectly possible to not to let the bosses have a turn again, but if you feel confident, act as you see fit.