Back when the level cap was 75, and there was an increased request among players that SE introduce Bahamut as an Avatar, SE made it very clear they had no intention of using Bahamut as it would downsize his greatness and not portray his appropriate power.
Well, things have changed since then. The cap is now 99 with an increase to 119 via equipment. A naked WHM with a JSW Club and Shield can enter the The Wyrmking Descends fight and beat him with ease. Where is his power now?
Sure, you could make another "Higher-Tier Battle" with his name on it, or you can give Summoners what they've been longing for. The ability to Summon the Wyrm King!
You already have a system in place that would more than compensate for his prowess and might. The Black Mage Spell, Meteor.
Using this same system I believe not only allows Bahamut to keep his status among gods, but allows players to harness that power.
Here's how I think it should work;
Need a minimum of 3 Summoner's to cast the avatar. (Similar to BLM Meteor)
In order to cast the avatar, you must have both 1 HR abilities available for use as using it will expend both, not just one.
Bahamut arrives, Casts Flare for big damage, and leaves.
Damage should be based off total Summoning Magic skill and Total MP used.
Which Flare he cast should be dependent on how many Summoner's are being used.
3-Mega Flare,
4,5-Giga Flare,
6-Terra Flare
Also have a minimum amount of Summoning Magic Skill needed to activate Higher Tier Flare's. Wouldn't want 6 Summoners with only 100 Skill using Terra Flare.
It's 2014, we are level 119, we can crush every "God" in the game that has not yet been converted to a Higher-Tier Battle.
Give us Bahamut already,
Thank you.