I saw someone asking about this and decided to make a list of the purple star organs which can be crafted at the Deathstate Portal and what they do. This is a bit of a spoiler. If the mod creators don't want this here, they need only say so and I'll take it down.

That said, I should also say: the actual stats on the purple star organs are all the same, which is "slightly better than the best normal organ of their type" so don't worry about that.

Also a warning: some of these can be basically considered cheat tools that will make the game very easy. I think it's fine, personally. The game can get pretty grindy at the end, so anything to make it less obnoxious is fine. You know, if Castlevania is too easy, stop using the Crissaegrim, and if Starbound is too easy, don't use these organs. :p

Head Slot

• Aggravating Brain - Gives bunnyhops. You continuously jump while holding down the jump button. You build up momentum while bunnyhopping and can move at incredible speeds.
  
• Ennervating Brain - An extremely annoying organ that makes you move like the random alien mobs in the game move. You're slow to start moving, but can build up incredible momentum. You might also have a damage boost? I haven't tested this one much because it's obnoxious.
  
• Observer Eye - Puts a "radar" on the screen. All enemies in range glow brightly, even through walls.
  
• Othello's Skull - Gives very substantial passive health regeneration.
  
• Samhain Skull - Depleting your energy causes you to take a medium hit of damage, but also instantly refills half your energy gauge at the same time, essentially halving the time it takes to get your energy back online.
  
• Shadow Hound Fang - Occasionally summons dogs around you. The dogs are useless in a fight.
  
• Cyan Eye/Cat Eye/Starchild Eye - Resists cold but takes extra damage from fire. Cat Eye provides immunity, and Starchild Eye heals you when you get hit by a cold attack.
  
• Golden Eye/Cat Eye/Starchild Eye - As above, except resists fire and gives weakness to cold. Also allows to walk in lava without harm.
  
• Magenta Eye/Cat Eye/Starchild Eye - As above, except resists electric damage and gives weakness to poison damage.
  
• Royal Blue Eye/Cat Eye/Starchild Eye - As above, except resists ALL element damage, but gives weakness to physical attacks. Allows to walk in lava, poison, and acid rain without harm.
  
• Ruddy Eye/Cat Eye/Starchild Eye - As above, except resists physical attacks but gives weakness to ALL element damage.
  
• Viridian Eye/Cat Eye/Starchild Eye - As above, except resists poison attacks but gives weakness to electricity attacks. Also allows to walk in liquid poison and acid rain.

Body Slot

• Elinberg's Heart - Boosts your attack damage while standing still, up to double damage. On its own, the Brutal Gug Stomach (see leg slot items) is better because you don't have to stand still for it, but they do stack.
  
• Ice-Pierced Heart - Creates a frost nova when you get hit, slowing enemies in its(very large) range.
  
• Modron Core - Allows short-term flight controllable with WASD. Replaces your jump tech, so you'll have to reequip your tech after unequipping the core.
  
• Soul Reactor - Causes constant energy novas around you, dealing moderate damage to everything nearby. This energy nova also instantly shield-breaks golem bosses in the Ancient Gateway dungeons.
  
• Spice-Fed Heart - Rapidly regenerates health at the cost of energy. Very good for physical attackers who don't use energy much anyway. :p

Leg Slot

• Bejeweled Spleen - Taking damage from enemies spawns pixels equal to the damage taken. Only damage from enemy attacks counts. Environmental and falling damage does not.
  
• Bilious Slimebag - Spawns a block of liquid poison when you get hit. Can be bad for you if you're not immune, but can be very good if combined with the Viridian eyes.
  
• Brutal Gug Stomach - Doubles your damage output. Also gives random 1 frame bursts of x10 damage.
  
• Saint Athenabry's Guts - Boosts passive energy regeneration, enough to use most ranged weapons basically endlessly.

Backpack Slot
All purple star backpack slot organs provide the same EPP protection as a Cooling EPP, and also...

• Butterly Lung - Hold down for a bit to get a boost to jump height. At full charge it can jump high enough to cause fall damage to yourself.
  
• The Brute's Lungs - Sprays fire in front of your while holding down. Low damage, not very good.
  
• Tumerichan's Lungs - Holding down for a bit will begin emitting healing pulses, healing you and everyone directly near you. Low healing and takes a while to start up... but hey, it's free healing.
  
• Vembrax's Lungs - Holding down will turn you into a statue. While in statue form you are impervious to attacks and immune to poison, but can not damage enemies yourself. Does NOT grant immunity to lava, and since you can't crouch in the air it won't save you from fall damage either. Still not bad, especially if you have the ability to summon allies to help you.