Other Demons which Akoni can summon
The Elemental Lords(Warcraft
Galakrond(Warcraft, through Necromancy)
Winged Dragon of Ra(YU-GI-OH)
Silfer the Sky Dragon(YU-GI-OH)
Obelisk the Tormentor(YU-GI-OH)
Vazdah(Ninja Gaiden 2)
And many more…
Akoni has incorporated these demons into his fold, some turned evil, some chose to join him. As a result, he has grown immensely in power, learning and utilizing all their dark magics in some way or another. These demons are but a tiny portion of what he can summon, the rest of the list? Nobody knows. What we do know is, he is their undisputed leader and master, their superior in all ways.
One enhancement he does to them(said in Archimonde page), is his utilization of Makyo Stars, which stores excess power, unlocks more power and limits the amount of energy the demons can access, while also gaining energy over time. Such is the power of the Makyo Stars, maximizing the powers of every demon in existence.
Other enhancements may include power bestowal, as well as power limitation, preventing some attacks from happening, reversing time’s effects, limiting the AOE of certain magic, and more. Just as the capabilities of magic are endless, so are Akoni’s capabilities and growth potential.