Hello Verdessence.
I'll start off with a simple explanation as to my reasoning for your materia ban.
You were told several times to use ultima on the boss, The logical reason I see for that strat is the fact the hitbox on that boss isnt consistent and and the boss nuke triggers alot quicker than conventional mako baha. Simply put, Its a different boss strategy.
After you were told to use ultima, You put a message in the chat that said you used ultima and you put a lenny after. I interpreted this as intentional grief, As its basically just laughing off what you were properly told to do. It doesnt help the boss nuked the team when its remaining hp was around 1200 - 1500, Though even if the boss died it wouldnt have changed the fact you were misusing your item. What you did is more or less the same as not using heal on baha ultima on mako.
The next bbo mako cycle, Ultima was used and the round went smooth.
In the future if you pick up an item on any map and dont know what to do it with it, Either drop it to someone who does or ask to know when to use it.
Also seeing as you claim you didnt "lenny" after putting the fake ult use in chat (Although irrelevant considering you put a fake use message to begin with) I went back to check and sure enough you did. Only reason im adding this is to remind you that trying to lie in your appeal and doesnt do you any favors.
Aswell as your mention of the person using the heal item, The team died due to the boss timer running out and nuking the team, Not because of baha ultima attack.