1st of all, sorry for the background noise. It's causing Berserk on me everytime it ruins a footage.

So, I defeated Trema, again, with Cat Nip strategy. Epic is that he didn't give me more fits than Paragon. And even more epic is Cat-Nipped Rikku's Post-Meteor survive with 1 HP!!! O_O Ahem, the strategy:

-The item sorting was important. Mana Spring was priority, as well as Mega Phoenix, Star Curtain and Stamina Tonic. Strong healing items such as X-Potion and Megalixir are essential as well.

-I adjusted the ATB to Slow and the ATB Mode to Wait Mode. Dunno if that causes any influence, but I passed Paragon with this.

-Arrange the Valiant Lustre GG very well. Put Lady Luck (wait what?) and Dark Knight as main priorities. Do what you do, but put Lady Luck and Dark Knight as neighbors, with a node between them!

-My adjusts for Yuna and Paine were completely defensive, with Valiant Lustre GG and accessories such as Champion Belt and Crystal Gloves. Rikku as Gunner with critical HP and Cat Nip, as well as Speed Bracer. As for GG, Highroad Winds. First, reduce the max HP with Wring and Bloodlust, then equip the stuff.

Edit: Under the heat of the battle and the whole nervousness, I didn't think about something better. You can actually use the same girl to bribe Paragon AND rain nines on Trema. So this will give you two DK's with tightened defense making the roles of casting positive status and revive the Cat Nip girl when she dies while trying to change DS. And you won't have only one girl and run risk of Game Over when things go wrong. Credits to AngelicaDeMortis for the idea! ^_^

-For Paragon, I tried my best to end the battle with minimal harm. I entered the battle with Yuna as DK, Rikku as Gunner with critical HP and Paine with Lady Luck. Wait! Lady Luck??? The idea is, Paragon doesn't attack the Lady Luck. His physical attack can reduce 600 HP from our very well improved defensively Dark Knight. If he attacks the Lady Luck, reset and try again, as he likely uses Genesis as 2nd attack, killing the party unless you have high MDEF and/or breaks HP Limit.

-If you Oversoul him, even better. Defeat some Omega/Ultima Weapons (Omega in Farplane or Via Infinito itself, Ultima on Chocobo Secret Dungeon or VI itself) then run away when you find an oversouled one. With high Luck, he will miss his physical attacks. The idea is use Bribe on him. You'll need 1,5 million to get him out of the battle and win a stash of Dark Matters. When I defeated Trema, I got 27 DM's from Paragon. ^_^ The bribe is very likely to succeed, while the Lady Luck (in this case, Paine) delivers the money to Paragon, heal or revive harmed girl. Remember: this is a Cat Nip-based strategy, so keep the Gunner with critical HP. If you use cure items with Cat Nip girl, you'll recover 9999 HP. If you oversouled Paragon, as recommended (although I didn't OS him :(), then you'll gain even more DM's.

-Now for Trema. Change that Lady Luck into Dark Knight RAPIDO! If you didn't put LL and DK aside each other, Trema WILL kill her. You'll save your girl and add 20 to your DEF and MDEF. On the change annimation, make Yuna use Mana Spring. Trema will kill Rikku, but not the DK's. Now you need to cast Protect on the party (Star Curtain?) to reduce Trema's constant physical attacks' damages. Then discharge Mana Springs on Trema to steal his MP. At least 5 of them. Flare is an insta-kill and he uses it sometimes. Always cure or revive your party, and DON'T USE TRIGGER HAPPY JUST YET! He has a remaining HP pattern for some of his attacks. Well, no MP, no Flare, no Ultima (used when he has less than 25% of max HP), no Demi. :D He will still do the charge motion for the black magics, but will fail. Priceless. Then use a Stamina Tonic to double your party's max HP, after this, cure the DK's, so you can have 9999 HP.

-Very well, I'm up to revive Rikku and do 9999 barrages on that old man. Keep your DK's cured AND under Protect. Meteor is used when Trema has 75% HP (you can see he praying, this is when he uses Meteor) regardless of MP. It causes fractional damage according to your max HP, but this damage can be reduced by Protect, as it's a PHYSICAL attack. Cure any damage caused by Meteor before reviving the gunner, and repeat the sucess 'til you win. He will charge Ultima at 25% of HP or less, but where is the required MP, sir? :P Keep going 'til you defeat him for good and get the lovely Iron Duke. (less info)