Some stuff are counter-intuitive or strange in some ways :

Edit : Don't comment why things are considered Impact of other stuff, I know, I understand, it's just things that people commented or talked about as counter-intuitive so I listed them here for other people, not as questions

• Kaï Haste is also a Buff, Drek’Ar Haste isn’t also a Buff... but it scales on Buff anyway (thanks for commenting on it)
  
• All Haste are Buff, which makes sense but is implicit
  
• Estelle Primary isn’t a Projectile, it's an Impact
  
• Atlas Primary is only Projectile, nothing more
  
• Atlas Secondary is only Creation, nothing more
  
• Juno Special is a Projectile
  
• X Secondary is multi target, but isn't Impact. The ingame wording game describes Impact as Area of Effect as similar.
  
• Drek’Ar Primary is both a Melee and a Projectile
  
• Luna Secondary isn’t a Projectile
  
• Era Special isn't a Impact
  
• AI.Mi Primary is a Projectile, even if Estelle Primary is not a projectile
  
• Zentaro scales very hard : Any synergies he has is at least a double
  As commented below :
  
• Atlas Primary should also be Creation, Secondary should be Impact,

Terminology oddities :

• Impact means Area of Effect if you trust the ingame wording guide, but isn't always consistent
  
• Hit refers to anything that affect anything, so something like Era's buff on an ally is a Hit
  
• Melee scales on Size
  
  Check the ingame documentations, there's a lot of stuff there.
  Not everything make sense tho, it's kinda dense by moment.
  I really hope Odyssey will change their naming conventions and be more rigourous and explicit with this. BTW, Odyssey, if you wanna hire me to do this, I'm a freelance game designer with 2 years of experience so call me maybe ? :d