I don't think there is anything Wrong with the Kol its just it only deals damage, you may as well use a Heavy Cruiser for this (same issue I have with the Tech Rebels Titan.. it Only deals damage) Compared to the other ships of its class.
The Radiance Can stop a ship using its ability's with detonate antimatter, it can kill a titan/cap simply by disabling its abilitys, it can change a fleet battle by 2-3x Aoe taunting and its final ability can hit multiple targets in a line.
The Kortul Devastator is the same, it can Stop channeled ability's, Drain enough antimatter to turn off ships, Cripple Rate of fire, Turn off strike craft's weapons causing huge late game power shifts, its final ability can AOE Debuff damage taken for all the fleet, 30% damage on 100 vs 100 fights... is 500 dps. (also doesn't help that power surge lets it 1v1 Any other ship)
Even if you gave the Kol 10 AM/sec it still only deals damage on its ability's and while Its a total BRICK and its hard to kill with huge hull, for the most part its meaningless because it doesn't DO ANYTHING, you can just ignore it.
Imo to Balance it with the other Battleship ships of the same class it needs something that makes it a Threat, thats not just Damage... Raw damage I can soak up and tank, CC / debuffs Cause issues
-Perhaps have Gauss Blast disable ships ability's, this lets it win vs the 8 other ships it previously looses to in 1v1 and gives it some late game threat.
-Perhaps give it an Taunt when it uses Force field.
-Add adaptive FF and finest Hour to all ships in an AOE radius when used.
-You could change flak burst to also give AM for every fighter killed