Final Fantasy Tactics Walkthrough

Another potentially difficult battle due to significant enemy forces, though as with most storyline battles, doing a significant amount of random encounters to grind along the way will help. You can do this pretty easily before taking this battle on, if you have been ignoring it until now. One possible strategy that stems from grinding is to make everyone an Archer and give them all Ignore Elevation, to jump up on the tower and rain arrows down on Argath.  

A better strategy that takes much less time to prep is to make Ramza a Monk with long-distance attacks, such as Shockwave and Aurablast. Adding Equip Heavy Armor to increase his HP significantly with that job makes him useful both at range and close-up, too.

Make the character that flanks Ramza and Delita a Black Mage and have him target Argath directly - not only will this damage him, but it will lure him in closer so as to try to hit one of your characters along with him.  When he does this, it's the perfect time to hit him with your most powerful attacks.

Otherwise, the enemy Black Mages will advance and do massive damage to you and you won't get much of a chance. You've got to do it all as soon as you can, otherwise his troops will overwhelm you, so if you get into trouble make sure you focus all offense on Argath.

Delita and Argath will target mostly each other with their AI in this battle. Therefore, keeping Delita alive will reduce the number of times Argath turns his weapon on the rest of your party, which means you will likely want to shift Delita to be an Archer (or other ranged attacker) himself, because it will give Delita the chance to inflict damage earlier than simply running into arrows for a couple turns before being in range. Adding Equip Heavy Armor to him will let him withstand some more abuse too.

Tietra can not be revived in this battle, though the guest-KO stars above her head might imply that she can. Don't spend turns trying to get up there to target her.

After the battle, Delita runs up to get Tietra's body when Gragoroth ignites the gunpowder within the fort.  The whole thing goes up in flames, engulfing Delita and Tietra, and Ramza turns his back on his life and runs.