'Swipe', Flame Breath, Gathering strength..., Still gathering strength..., Whole Lotta Strength, Bruiser Tail*37.5% max HP damage and inflicts delay., Crushing Tail*50% max HP damage and inflicts delay., Megaton Tail*62.5% max HP damage and inflicts delay.
Normal: "A dragon of formidable size, with strength to match. It's powerful breath attack can deal terrible damage." Oversoul: "A dragon of formidable size, with strength to match. It stores up its strength and then unleashes devastating attacks, so be prepared!" — Scan
Strong physical attacks are the way to go here. It is wise to use high Defense dresspheres as well as Light Curtains to avoid the damage it can do to the entire party in one blow, and it is also wise to stock up on Mega-Potions as well as having Fire resistance to avoid its Flame Breath attack.
Armor Break and Power Break help weaken it enough to where the party can take less damage and dish out more damage, but the party should keep HP high. High evasion is helpful, as it will allow the girls to avoid getting hit by everything except Flame Breath.
In the Fiend Tale endings, a notable Claret Dragon was trapped in a cycle of reincarnation where he was reborn a dragon hunter who is killed by dragons and reborn in his fiend state to be killed by other dragon hunters. Though he hated his fate, Claret Dragon allowed a monk to kill him to overcome his fear of death, but ended up getting closure as he departs to the Farplane.