My ideas for passives:
City Hunter - can use rebreather as a secondary gear item to replace bio mask if blown off.
Mr Black - has passive Spectral Awareness perk and Target Isolation lasts an additional 2 seconds (inspiration is heart beat sensing vision mode he had in the movie)
Jungle Hunter/Captured/Hunter - has ability to use red heat vision mode like in Predator 1987 when Jungle Hunter takes off bio mask, only active once mask is destroyed, cannot scan Fireteam members nor use Target isolation
Jungle Hunter, City Hunter, Mr Black, Falconer, Captured, Wolf (all movie Predators) - reduced clicking noise volume and frequency while cloaked, 20% speed increase for 5 seconds upon cloaking.
Berserker, Mr Black, Viking, Samurai - 10% movement speed increase (permanent) and 10% damage reduction for 20 seconds upon mask destruction.
Mr Black - Increased sprint speed when getting shot in the back by 20%
Wolf - 10% damage reduction and 15% increase in melee damage output after mask destruction (he already has a minus % in melee damage by default)
Samurai, Exiled, Valkyrie, Falconer, Scout - Wrist Blade attacks deal 15 bleed damage per slash.
Scout - reduced heat vision eye flash visibility
Elder - can aim Plasma Caster perfectly accurately after mask destruction
All Predators:
Will have at least some bullet damage resistance, Wolf will have the highest bullet damage resistance, various levels of passive Predkour movement speed and mount speed increase, Cleopatra will have 15% knife damage resistance because come on look at her armour, all lower energy Predator classes have additional energy equivalents of light bender and heated added for specifically Berserker, Scout, Exiled, Falconer, Viking, Emissary(passive modified reserve), Alpha Predator.
Alpha Predator will deal more melee damage the lower his health drops, when explosives or Plasma weaponry from Fireteam hit his bone armour it instantly regenerates parts of his energy, has a passive of reduced parry stun duration and reduced parry efficency against his melee attacks, has passive Dithered lens with moderately reduced visual effect(because he was Ancient and likely didn’t have proper targeting lasers despite him being shown so in game).
Perks I would add:
1st one goes to @ScOp_StUrMi for credit - when at full health deal higher ranged damage, and at low health deal higher melee damage
Perk to reduce explosive damage - 3 points
Perk that reduces spot duration - 2 points
Perk that reduces clicking noise frequency - 2 points
Sadist - all melee attacks deal bleed damage, Bow will deal poison damage over time, Plasma attacks deal very slight burn damage - 4 points
Technician - Fireteam heals from dropped kits or kits from the map have reduced heal effectiveness when damaged from a ranged attack, and ammo crate effectiveness is reduced when Fireteam are at above 75% health - 4 points
Added mechanics etc I would add:
When Predator runs into a Fireteam member head-on, the Fireteam player gets knocked on the ground and sustains 25-50 damage depending on how heavy the Predator class is. This will stop body blocking problems.
Predators can choose a third weapon instead of a 3rd gear item if they choose.
Plasma Caster shots will blind a Fireteam member like a flashbang momentarily if sustained to the face, blinding effect will last longer on night maps and will have a wider effect on night maps.
If a Combistick throw head shots a Fireteam member it will deal 200 damage and should down a Fireteam member regardless.
Yautja Bow head shots will deal 100 damage regardless, can increase with Down Range and other specs.
Wrist Launcher should have alternative variant which is effectively a wrist mounted Plasma Caster and shoots a Blue projectile with the same effect, but is energy based and can have increased damage from perks and specs.
All Predators have incredibly reduced footstep noises and make little-to-no noise whilst traversing in the trees. Effect is increased on light classes including Scout, Exiled, Falconer, Valkyrie, Alpha.
Audio decoys actually make noises that don’t give the Predator away e.g. they make the correct roar for the Predator ingame for example if a Female Predator, the decoy makes a female roar, if its a City Hunter, it makes a City Hunter roar noise. Audio decoys should also make fake cloak noises, and fake healing noises.
Apologies for the random layout of these I honestly thought half of them up on the spot lol.