Gatewalkers Deviant Abilities

https://downloads.paizo.com/GatewalkersPlayersGuide.pdf

Deviant Powers Deviant Abilities

The Deviant Abilities listed on this page should roughly line up with how Class Feats for a given class rank -- a Deviant ability ranked 3/5 should roughly fall in line with a Class Feat but it might be a good idea to give the tiebreaker to the Class-specific Class feat in most cases.

Dragon

The backlashes for the Dragon Deviant Abilities aren't too harsh and it allows you to turn yourself into a Fireball if you're willing to risk the damage on yourself.

Blasting Beams (3/5)

I think of Blasting Beams as a 1 action cantrip that everyone has access to and I'd consider that to be the baseline for Deviant Abilities. There will be points in the character's life that Blasting Beams will be less accurate than a weapon attack or spell attack since Class DCs typically lag behind Weapon or Spellcasting proficiencies but it's a decent use of a feat (especially if you can get it for free as part of the adventure or through your background).

Consume Energy (2/5 or 4/5)

Let's get the bad part out of the way first. If you aren't in a campaign (or a situation) where your deviation damage type shows up consistently, this will almost always be a dead feat. It's hard to trigger but it is a decent chance at a nearly resourceless Counterspell (it's something like 8 uses with 4 success on average) -- bonus points for the temporary hit points but that's going to be a small number most of the time.

If you know you'll encounter Fire or Frost enemies throughout the entire adventure, this feature is incredible. You're likely preventing a ton of damage, even in cases where you've triggered backlashes (unfortunately, if you trigger a Backlash that counteracts Consume Energy so it can be inconsistent).

The ugly part to Consume Energy is how DCs are determined and challenged. Full casters will typically get more mileage out of this feat because their proficiency bonuses earlier than other classes (and they get to use their spell casting modifier as well); if a character without a spellcasting DC attempts to Consume Energy on a spell, their bonus is likely to be their class DC - 10 and that typically progresses a little slower.

Troll

Bone Spikes (2/5)

Titan Swing (3/5)

High-Speed Regeneration (4/5)

The only reason I don't have this as a 5/5 is that it has to be compared against every other feat in the Pathfinder 2e system and equally impactful for all types of characters. The biggest problem is High-Speed Regeneration is probably better for martial characters and a lot those martial classes have Attack of Opportunity available at the same level as this feat.

Your DM can prevent this free action from triggering and could make your life slightly harder but I don't see why you wouldn't be able to use this free action out of combat to provide yourself literally free healing at the low cost of needing to eat some food.

Death Awakening (2/5): Essentially Orc Ferocity for anyone that's apparently a free action instead of your reaction. If you want this sort of effect, I'd look for it in Ancestry feats instead of a level 10 Class Feat.

Speed Awakening (2/5): High Speed Regeneration now grants a 10 foot movement speed boost for no action cost, I like this more than the other Awakening power but it's not that much stronger, especially after considering how common status boosts to speed can be. It's nice for when you can plan your turn out and know you need the extra movement speed but a 10th level feat to do it is too much.

Wraith

The backlashes are awful for your character, so you're going to notice a pattern for most of these rankings.

Eerie Flicker (2/5)

Concealment grants a 20% chance to miss (DC 5 check) on all attacks for the rest of the round. The fact that this works on all subsequent attacks is the only reason this isn't a (1/5).

FAQ

When a Deviant Ability, like Blasting Beams, calls for an attack, what is the attack modifier that should be used?

The short answer is add (Class DC - 10) to the dice roll.

https://www.reddit.com/r/Pathfinder2e/comments/y4fa6m/can_a_rogue_sneak_attack_with_blasting_beams/

Deviation Saves and Attack Rolls
Many deviations allow for a saving throw or have other abilities that change as you go up in level. The DC for any saving throw called for by a deviation is the higher of your class DC or spell DC. The attack modifier of a deviation is 10 lower than that DC, unless the deviation calls for a Strike, in which case the attack modifier is the normal attack modifier of the Strike. A deviation's counteract modifier is equal to your counteract modifier.

How does Counteract work?

https://2e.aonprd.com/Rules.aspx?ID=371