Captain Blix is a ship pilot in Captain Impostor that assaults the Narcissus after reaching Juliet clone power for the first time. Blix's ship is Kilo-level, and uses Ramming Spikes, which operate at over 100,000 J of damage per meter per second. (See Kilo for more weapon details.)
Overall, Blix is a very powerful ship to copy. It's one downside is the lack of range; any attempts to fire weapons will result in immediate destruction of the ship due to the lasers pointed around the command module.
Generally, the best way to deal with Blix is to copy him immediately at Juliet. While this means the player's ramming spikes will operate at half efficiency (being a tier lower), the ship will still excel at removing Blix's weapons, especially if the player is able to attack from the side. It is nearly impossible to retain all Spikes, but as long as the player is able to attack Blix's girders, he will continue to lose weapons.
The command module is protected by a Kilo-level shield, it is difficult to generate enough momentum to crack it. The player will have to charge from a distance, then use a number of swift, close-range swipes using the side-boosters. If done correctly, Blix's ship will eventually be reduced to nothing.
The sole other useful ship type to deal with Blix is to find a line ship with Prismatic Lasers. At Juliet, such a ship will be extremely powerful and, given enough time, could decisively wipe out Blix's weapons. Unfortunately, this means finding a ship with good dodging ability; Spikes are very tough and take many more hits to destroy than other weapons at tier. Besides that, the player will have to dodge Blix's attacks for a while with only the Narcissus, which can be tough given Blix's speed.