What you can expect @ each difficulty level:

There are three pools of scripts the prototype can pick from - offensive, defensive, and superweapon. The defensive scripts are:

• Adaptive - the prototype will gain damage resistance vs. the damage type it has suffered the most of. Damage resistance is updated every 30 seconds.
  
• Iron Curtain - once the prototype drops to 25% HP, it becomes invulnerable for 1 minute.
  
• Phasemode - the prototype will switch between being invulnerable for 10 seconds and vulnerable for 20 seconds.

The offensive scripts are:

• Overdrive - the prototype will switch between doing double damage for 10 seconds and normal damage for 20 seconds.
  
• Frenzy - the prototype will gain 5% damage every 30 seconds while below 33% health (this is additive)
  
• Avenger - the prototype will gain 20% damage every time one of its allies is killed (this is multiplicative / expoential)

The superweapon scripts are:

• Torpedo slammer - constantly fires volleys of torpedoes at a randomly chosen target.
  
• Siege gun - fires a big yellow blob at a randomly chosen target - blob does massive damage on contact.
  
• Laser sniper - the aforementioned "death laser" - locks on to a randomly chosen target and fires a laser beam that does high damage on contact.

Every time you take this mission, it will have a hidden difficulty level chosen - this is reflected in the difficulty of the mission (Difficult / Extreme / Death Sentence) but outside of Death Sentence (which is always 10), there is no way to know for sure exactly which difficulty you are getting.

1 - 5 (Difficult)

• A group of 4-6 ships will always spawn with the prototype.
  
• Prototype will get x3 damage and x3 turrets compared to other ships in the region.
  
• Prototype will get one randomly chosen defensive script.

6 - 7 (Extreme)

• Prototype will be larger.
  
• Prototype will get x4 turrets compared to other ships in the region.
  
• Prototype will get one randomly chosen offensive script.
  
• One additional ship will spawn in the initial escort group.

8 (Extreme)

• Prototype durability (not size) increased by 25%
  
• Prototype damage increased by 20% (this is an additional multiplier - so it would have 3 * 1.2 additional damage)
  
• Prototype will get x5 turrets compared to other ships in the region.
  
• Prototype has a hyperspace blocker.
  
• Prototype gets a 2nd randomly chosen offensive and defensive script.
  
• Whenever the prototype drops to 50% health, or is the only remaining ship, a group of 6 reinforcement ships will spawn.
  
• One additional ship will spawn in the initial escort group (for +2 total)

9 (Extreme)

• Every 30 seconds, the prototype will buff one of its allies with a randomly chosen script.

10 (Death Sentence)

• Prototype durability (not size) increased by an additional 25% (50% total)
  
• Prototype damage increased by an additional 20% (40% total)
  
• Prototype gets x6 turrets and x4 damage compared to other ships in the region. (This would be a total of x5.6 damage)
  
• Prototype has a stronger hyperspace blocker.
  
• The initial set of escorts + the reinforcement wave are stronger ships.
  
• Prototype will have all offensive / defensive scripts.
  
• Prototype gets one superweapon script, chosen at random.