Up to the "left or right" choice during the diamond battle, this is what the various routes get you:
High Corruption level: 20-27
Kill everyone and make all the correct choices: 27
-1 spare Demi
-1 spare the cops
-1 spare Jake
-2 spare Danica
-1 fail to make the Minyak submit by either not klling Danica or prematurely killing Bailey
-1 failing to get enough Power to consume Kenny
Having 20 or more corruption at this point and not wearing the helmet unlocks deadend37.
These are the maximized stats depending on the playthrough (and assuming you picked the horn):
Corrupt Power: 105 / 26 Skill
Corrupt Skill: 103 / 27 Skill (Delay training events to have 9 Power when training with Alice after she gets her powers)
Pure Power: 100 / 26 Skill (Impossible to get Valravn respect)
Pure Skill: 99 / 27 Skill (Fails every power check in the game)
Power/Skill related Scenes:
| Pure Skill | Pure Power | Corrupt Skil | Corrupt Power |
Deadend3 | No | No | No | Yes |
Kenny Eaten | No | No | No | Yes |
Valravn Respect | Yes | No | Yes | Yes |
Save Laurie | Yes | Yes | Yes | Yes |
Meet Aglaecwif+Save Laurie | No | Yes | Yes | Yes |
Deadend39 | No | Yes (Can't save Laurie, must get power from Aglaecwif) | Yes (Can't Save Laurie, must get power from Aglaecwif) | Yes |
Save Laurie+Deadend39 (No Aglaecwif) | No | No | No | Yes (Cannot meet Agalecwif, Must fight the Wepwawet correctly) |
Notes:
The game currently does not consider Corruption as a morality meter. While these 2 have some overlap, it's possible to have high corruption and high moral stat. To access the moral stat you need to enable the console.
The Eye says that it's possible to lose the corruption ending if you don't eat Kenny.
This means that only the Corrupt Power playthrough meets all the requirements.
If I had to bet, I'd say that between Kenny and Bailey, eating Bailey is the important choice and Kenny won't be that important, but that's just a feeling I have. The Eye's dialogue allows the possibility of reaching this end even if you miss eating someone and Kenny is a good candidate.
While Deadends show some important stuff, they are still deadends.
Most of the choices presented here do not actually have an impact on the story as of latest update but that could change.
This is what I think about their potential.
Eating Kenny -> Possibly affects the high corruption/consumption ending.
Valravn Respect -> Possibly affects Valravn's behavior down the line. Possibly allows for an alternate ending.
Meeting Aglaecwif -> Possibly allows for an alternate ending. Possibly affects a combat scene down the line. Possibly adds an ally down the line.
Saving Laurie -> Possible sex scene, Possible "harem" member, Possible girlfriend for Deryl.