[Spoilers] Devil Tierlist as of Chapter 174

Devils not included:

• 2nd Incarnations: Even if it is stated that a devil is weaker than when they first appeared it still means at their height they were at a certain strength.
  
• Fiends: Fiends don't necessarily encompass what an actual devil is and what the devil can do.
  
• Hybrids: Same reasoning as Fiends.
  
• Devils that have only appeared in contracts: Similar reasoning to Hybrids and Fiends, as we don't really get to see the full scope of their power. Exceptions are made for Future and Ghost Devils since we do see them in the story fully and we see certain abilities outside of what they offer to their contractor.
  

S:

1. Darkness Devil: This shouldn't need too much explanation but Darkness Devil is very clearly the strongest devil that we have seen so far and I'm sure we have only really seen a small amount of his power.
   
2. Eternity Devil: Though beaten fairly early in the manga, I still feel like the Eternity Devil has the opportunity to trap and ultimately kill pretty much anyone. If we extend the meaning of eternity with use of things said in the manga it can be assumed that the Eternity Devil can even trap characters that have teleportation abilities, like Hell Devil, as Aki says he can't summon Fox Devil due to being "cut off from the outside". Implying that Eternity Devil can just endless barrage you until you lose, which Denji would of lost if he hadn't thought of the idea and been helped by Himeno. The thing stopping it from being #1 is the fact that to be the most effective the Eternity devil needs the person to be in it's stomach as we see in the 2nd incarnation it dies easily when someone is outside of it's stomach.
   
3. Curse Devil: Though we see very little of the Curse Devil and though we only see it through contracts, I still think it deserves to be on this list because it seems that cursing is all it can do, unlike a devil like the Claw Devil which would have probably more abilities than just a swipe. Due to Curse Devil's ability I think it could very easily one shot every character, though we don't see the Curse Devil set onto a devil. What stops it from being #1 though is the same as Eternity Devil, set up. This might just be the Curse Devil messing with it's contractors requiring 3 hits, but it can be assumed that that's not the only way it can attack but might just need 1 interaction with a cursed object to activate it.
   

A:

1. Gun Devil: Gun Devil is very effective and fast but seems to be easily overwhelmed by Makima.
   
2. Chainsaw Devil: Chainsaw Devil is similar to Gun Devil, minus incredible speed. But also seems to handle Makima's barrage slightly better than the Gun Devil.
   
3. Typhoon Devil: Typhoon Devil seems to be extremely strong but hampered by it's body being vulnerable.
   
   • Side Note: I would say that Gun Devil is stronger than Chainsaw Devil but I do think the distance in strength is minor.
     

B:

1. Angel Devil: Angel Devil seems decently strong being able to do massive damage to the Chainsaw Devil. The problem is what we have seen out of Angel is dependent on Angel having enough life force to act, this means if you are able to make Angel waste enough lifespan you win as his only real way to gain in a one on one is to touch the opponent meaning death against most S and A tiers.
   
2. Ghost Devil: Ghost Devil seems to be decently strong overwhelming Katana Man, but seems to be easily defeated by Snake Devil and doesn't seem to keep intangibility when fully formed.
   
3. Mannequin Devil:
   
4. Falling Devil: Falling Devil has good survivability but outside of that her ability seems to be easily counter acted.
   
5. Stone Devil: Stone Devil has a problem that some other B tiers have, the problem of surprise and how that would be taken away in a one on one fight. But unlike Snake and Fox Devil Stone can have a extremely useful ability on hit instead of just damage.
   
6. Control Devil: Control Devil is only really a set up devil. She needs prep time, with it the Control Devil can do pretty good, but separating the Control Devil from those she is controlling or killing her when she reincarnates in Hell or Earth seems to show she cannot do much on her own.
   
7. Snake Devil: Snake Devil seems to only be useful due to the surprise factor and other than that doesn't seem that strong.
   
8. Bat Devil: Bat Devil seems to be decently strong but is hampered by his need to consume blood.
   
9. Doll Devil: Seems to be a useful ability being able to turn potentially anyone into a doll but similar to Angel the touch aspect is what makes it hard to place them higher. Plus the effect doesn't work on devils, fiends, or hybrids making the window very narrow.
   
10. Zombie Devil: Similar to Makima but far less effective as it seems all abilities or intelligence is removed when zombified. Seems though to be good at overwhelming opponents.
    
11. Fox Devil: Similar to Snake but lacks the ability to spit up things consumed.
    
12. Guillotine Devil: Seems reasonably strong, nothing too extreme.
    

C:

1. Cockroach Devil: Seems decently strong but easily overwhelmed by Denji.
   
2. Spider Devil: No real combat abilities but a useful ability none the less.
   
3. Leech Devil: Seems to be easily defeated by Fox Devil and only does well against a weakened Denji.
   
4. Muscle Devil: Seems to not be able to control all muscles when made contact with making it very easy to defeat at times. Also I'm unsure how Muscle Devil would interact with other devils.
   

D:

1. Tomato Devil: Beaten by a pre Chainsaw Man Denji.
   

Unknown:

1. Chicken Devil: Though it can be assumed Bucky is very weak, it was never actually shown the combat abilities of him.
   
2. Blood Devil: Can be assumed to be decently strong through Power but didn't show enough as the Blood Devil to say.
   
3. Future Devil: We only see the Future Devil's abilities through Aki's contract but it is reasonable to assume the Future Devil can see the future and has teleportation of some kind. Whether or not the Future Devil can change the future I don't know. It could also be that the Future Devil didn't teleport but was appearing as he was when he relayed the information to Aki about how Aki would die. So the Future Devil we see when Aki dies isn't actually the Future Devil but is more like a vision of the Future Devil looking at the future.
   
4. Hell Devil: We don't see any combat ability but it could be assumed that the Hell Devil is decently strong as the fear of Hell or the ideas of a punishing afterlife seem consistent across cultures. Not to mention all Devils come from Hell, increasing the overall fear of the place, but it could be that the Hell Devil only is for the fear of the Hell we see in the Chainsaw Man universe which would mean knowledge on Hell is probably extremely restricted to the general public. Hell Devil could be for the Chainsaw Man Hell and a Afterlife Devil, Punishment Devil, or Death Devil resemble the ideas of a punishing afterlife instead.
   
5. Punishment Devil: Seems decently strong but it's strongest feat, seemingly beating the Gun Devil, is off screen.
   
6. War Devil: We don't see how the War Devil by itself would fight, especially considering it's ability to increase weapon strength with connection making it very difficult to predict how the War Devil would work without a host. With Chapter 176 we have seen what Yoru could do on her own, but given how she doesn't seem too keen on the idea of using Gun Devil and Tank Devil it can be assumed she wouldn't normally do this. Also what counts as a child of Yoru is vague, is everything that can be used as a weapon considered a child? Would she be able to use Chemical Warfare Devil, since it's not really a weapon but is used in war? Also with how hesitant Yoru was to do this it can be assumed that turning a devil into a weapon has some affect on the devil, maybe even permanently, so again in a normal fight how likely Yoru would be to use a devil as a weapon is hard to say which is why she will stay in Unknown until more info comes out.
   
7. Famine Devil: We haven't seen her fight yet.
   
8. Aging Devil: We haven't seen any abilities so far, besides the mirror one but that is extremely vague and not well understood.
   
9. Justice Devil: Maybe we have seen all he can do but it is unlikely.
   

Be free to correct me or post your own tierlists.
Tierlist I used: https://tiermaker.com/create/ultimate-chainsaw-man-characters-part-2-included-100-ch-152862
Some pictures might not look similar, that's just because I include those not present in the tierlist or had to add them after making it due to forgetting.