Battle of the Oskara Nebula

The Battle of the Oskara Nebula was an engagement between the Unvari Hegemony and Battlegroup Gargoyle of the Systems Navy, led by Rear admiral Evan Holmes. Using their far more advanced technologies, the Hegemony quickly gained the upper hand against the human fleet, resulting in the destruction of many of their forces.

Background
Rear admiral Evan Holmes oversaw the transport of materiel to distant colonies to ensure their safety. Under the advisement of his Executive Officer, his fleet took a shorter route through the Oskara Nebula, despite it not having been cleared as of yet. His ships exited FTL and set a new course through the nearby Nebula, all the while deploying probes for future scientific use and threat detection.

As they travelled through the nebula, they gathered samples and data, cataloguing it within their archives, all the while keeping watch in case they were attacked. Approaching the centre of the interstellar cloud, General Calarth and his forces waited for their opportunity to strike at their targets.

The battle
Upon reaching the middle of the Oskara Nebula, the Unvari Hegemony that laid in wait sprung their trap, coming into realspace with two light battleships, 4 heavy destroyers, and 8 escort frigates, each with a special task. As the Unvari heavy destroyers and a light battleship engaged the human warships, the eight escort frigates formed a perimeter around the flagship, escorting it so it may perform a boarding action and keeping it safe from hostile units. Realizing what was happening, Rear admiral Holmes ordered all crew and onboard troops to prepare for boarding action and to expunge data from their ship's systems, while sending its own escorts to deal with the enemy frigates.

Although Battlegroup Gargoyle did their best, the Unvari fleet managed to overwhelm the defenders and close in on their command ship. Now in an appropriate position, General Calarth utilized ancient technology to teleport himself and his forces onboard the SNV Barca, bypassing typical techniques and taking the defenders by surprise. Realizing the threat, Rear admiral Holmes ordered his embarked troops to secure the closest vital ship systems and to ensure they didn't fall into enemy hands, all the while he led a contingent to confront the boarders directly, leaving his Executive Officer in charge. As Hegemony troops moved through the ship, General Calarth reached the hangar bay and proceeded to open the bay doors, allowing additional troops to enter the ship. With his reinforcements, Calarth proceeded to attack all local personnel.

Despite their surprise, the human defenders reached the hangar before the attackers left, blocking them from accessing other parts of the ship. As the firefight continued, all remaining crewman were armed and sent to the hangar to assist in securing it, although they still suffered heavy losses when they were confronted by General Calarth and his entourage. However, the Hegemony eventually managed to push through the defensive line, prompting Rear admiral Holmes to declare a ship-wide evacuation. Having in hand a remote self-destruction device, Rear admiral Holmes detonated the ship's reactor core after all escape pods reached a safe distance, killing all Hegemony forces onboard and those that remained in the area. Nearing this time, an additional United Systems battlegroup and proceeded to engage the remaining enemy fleet.

Aftermath
With the destruction of the battlegroup and its cargo, the Third Colonial Diaspora was slowed by a noticeable margin, but not enough to scrap the operation itself. Rear Admiral Evan Holmes, while achieving a Pyrrhic victory, was demoted to the rank of Admiral and sent to a distant outpost for putting himself and his entire command at an unnecessary risk. Despite the losses, the United Systems had recovered the teleportation technology used by the Unvari, eventually managing to adapt it for their own uses and to develop counter measures to prevent teleportation in the form of the Hekate Enforcement System, which prevents any and all forms of teleportation within its radius.

With the death of General Calarth, his faction went into chaos, only to be wiped out by rivals less than ten years later.