Archmage: The Archmage’s tower reaches up to the Overworld, and he maintains relationships with the leadership in the Anvil Cloudlands. A number of hard-to-find magical ingredients can only be found reliably in the Cloudlands, so he regularly sends up groups of adventurers and apprentices to retrieve things. A number of his people inhabit Ouranoupolis maintaining some magical wards similar to those in the Empire.
Crusader: Though his interests primarily lie in the Land below, the Crusader occasionally sends agents to the Overworld. Sometimes you need a few dozen crossbow bolts fletched with angel feathers to take down a particularly death-resistant demon. A few of the Fallen angels make their way down to the Land and join the Crusader’s legions.
Diabolist: The demons she rules love chaos. If demons could estabish a foothold in the Overworld and simply drop their spawn onto the Land from a flying realm, that would be some serious bad news for the Empire. Some Fallen Angels might work with her out of sheer spite for the angels in Skyhall.
Dwarf King: The ruler of Forge has more interest in wealth below the earth than above the clouds. Occasionally an item of power will cause him to send agents, but his interests in the Cloudlands are limited. The massive cloudform The Anvil has been known to linger over the dwarven city of Anvil for suspicious durations.
Elf Queen: Those damned Sky Elf heretics in the Cloudlands have forsaken their Queen. The Elf Queen maintains a policy of public dismissal and private war with the Cloudland’s population of High Elves that have splintered off and formed their own little society among the clouds.
Emperor: The Emperor can’t maintain an official military presence, but he makes a point of it to keep an emmisary in the Cloudlands to keep him informed. Any threats to the Empire from the Overworld are met with a swift dispatch of Imperial agents or adventurers working for him.
Great Gold Wyrm: The Wyrm was once an ally and confidant of the Angels that inhabit Skyhall in the Cloudlands. Golden Paladins still make a pilgrimage there to continue the relationship in his stead. A Couatl named ‘Thundrous Retribution’ associated with him makes a sort of home in the Cloudlands.
High Druid: The High Druid regrets how large the human settlements in the Overworld have gotten and threaten it’s unique ecosystem. She communicates with Sky Druid sects via a variety of means. She is particularly concerned with the well-being of the Anvil. A threat to the largest living cloud in the Overworld will be of concern to her.
Lich King: The affairs of the Lich King don’t appear to make any direct moves to sieze control of anything in the Cloudlands. But he plays a long game, who knows how he might be trying to influence events more subtly.
Orc Lord: ORCS CAN’T FLY. CAN’T REACH CLOUDS. IF ORCS STEAL WINGS…
Priestess: The speaker of the Gods of Light maintains an active relationship with chapels and temples in the Overworld, including the Cloudlands. When a chapel passes near Cathedral, many priests take a missionary journey to the Overworld. A substantially smaller number return. She does try to discourage outright worship of the Anvil itself, though.
Prince of Shadows: One would have to be a fool to think the Prince doesn’t have his hands in this area. When the Cloudlands pass by a tall object that reaches the Overworld (such as Highdock), you can bet he’s got people involved in any trade that goes on. He’s been rumored to hide objects belonging to powerful entities up in the Cloudlands for safe keeping.
The Three: The Blue has some plans and agents in the Cloudlands to harness some magic there. The Black keeps her eye on an Empyrean Black dragon that makes his home in the Cloudlands, making sure he doesn’t build up the power or hubris to challenge the Iconic Black. The Red occasionally terrorizes the Cloudlands when its link to the Archmage’s wards weakens far from the Empire.