Dark Ifrit is one of the Dark Aeons and spawns after you have obtained the airship Fahrenheit. There are a few steps that you have to do in order to initiate the battle against Dark Ifrit though so you wouldn’t normally encounter him randomly.
The Dark Aeon is located on Bikanel Island in the Sanubia Desert. Travel all the way to the north side of the desert, where the Al Bhed town of Home used to be located, and speak to the Al Bhed woman standing nearby. The battle will begin after a few lines of dialogue.
Each of the Dark Aeons, including Dark Ifrit, are considered superbosses and are some of the strongest enemies that you can fight in the game. As such, you will need to ensure that your party is fully leveled, has their best weapons and has their stats maximized as much as possible. Refer to the Advanced area of the Tips and Tricks section for additional details.
HP: 1,400,000
Elemental Affinities: Absorbs fire damage, Holy damage hits for double
Immune to Sensor
Dark Ifrit is not too difficult to defeat compared to some of the other Dark Aeons. Similar to the battle against Dark Valefor, you need to be prepared to deal with his Overdrive attack which will instantly kill your party members. You can either have Yuna summon an Aeon just before the attack or have your party members cast 
Auto-Life on one another.
You can Steal the following items during the battle:
Mega Phoenix (x2) (common)
Elixir (rare)
And Dark Valefor will drop the following items when it is defeated:
Dark Matter (common)
Master Sphere (rare)
