Stars of Akarios: Legendary Weapon Upgrade PackExpansion

From BoardGameGeek:

The Legendary Weapon Upgrade Pack expands the capabilities of the base game by adding legendary weapon upgrades that make players' ships more powerful and unlock new tactics. Unlike standard weapon upgrades, these cards have special properties that can dramatically change the course of a battle. Increased accuracy, increased damage, special effects against specific enemies - each upgrade adds depth to the strategy and allows you to adapt the ship to your style of play. The set consists of 6 Legendary Weapon Upgrade cards which can be added to the game at any time. All these improvements are available on any market. A player can spend 40 credits to purchase one Legendary Weapon Upgrade. Only 1 Legendary Weapon can be installed on each ship.