There are very few lines from either Ajora or Altima in the game, however you hear references to both throughout it once the Brave Story is 'discovered'. Ajora himself only has 4-5 lines [one is Alma & him fighting over the body], and Altima has about the same.
"Are you...trying to...stop my...resurrection... I won't...let you...come out...my servants."
--Ajora, after splitting Alma out of the body into her own. After this he calls forth ultima demons.
"I will not let anyone prevent my resurrection...!"
--Ajora, before unleashing Altima. Probably the quote that you'd think of first for Ajora.
"Prepare yourself... powerless ones!"
--Altima upon appearing and the initiating of battle.
"No... This can't be... You're the descendant of the one who killed me before. No...I won't be beaten... I will not be beaten..."
--Altima, after you fight her awhile and deal enough damage, to Ramza. Then she transforms into her ugly form.
"I will... kill you!"
--Altima, post transformation. I suppose having to turn ugly in a fight would make anyone say this.
--Altima, upon dying. Probably the best way to sum up Altima is with this line.
References to Ajora or Altima
"No, it will work... It just needs more... You didn't hear? It just needs more blood... Lots of blood is needed for the Angel's resurrection. Much bloodshed since Ajora's death, but I guess it wasn't enough... I guess I'll have to go on another rampage...!! Heh, heh, heh.... Don't worry... I'll 'sacrifice' you first."
--Vormav, before becoming Hashmalum.
"Shit! It's still not right. If only 'Bloody Angel' were here this wouldn't have happened..."
--Adramelk, upon defeat.
"Maybe they can't use their power outright? The Lucavi of legend, was an unbeatable, ferocious monster."
--Meliadoul, after Zalera's defeat. The explaination we're given is that without Altima, they cannot achieve full power.
"Did they find a suitable 'body' for him?"
--Elmdor, talking to Vormav at Limberry. I noticed it's him here, but bloody angel in his next line [who is female...]
"Really... Now we have to bring back 'Bloody Angel', using the 'Ultimate Power'! ...Then even without the stones or a suitable 'body', we can come and go at will. Did they find a good 'body' for 'Angel'? Don't tell me it's that girl..."
--Elmdor again after Vormav replies from the above.