Can I do anything with...

[Xafron Chi]

Big Daddy? I found her in a dungeon and she doesn't attack on sight, and I can talk to her. It says she is a Machinegod.

Either with gifts, or allying myself with Mani of Machine? Or something else?

[Country Square]

When you kill a big daddy, a little sister spawns, if you've been to little garden, which is west of the starting meadow, you can get mechanical balls there, toss one at her and she'll join your party, bring her back to little garden and you'll get a reward. You can also kill her, and she'll drop a corpse that greatly increases stats, but then little garden won't hand out rewards for saving them as often. (At least presumably, this is how it was in elona)

[Aeth]

if you can talk to them you might be able to gift them items and use affection raising actions to befriend them

[Akameka]

they are a bioshock refference.
They are very powerfull neutral monsters that you should aim to kill once you're strong enough. They will leave a little sister once killed. Either capture the sister with a mechanical ball and bring her back to the garden to free her, or kill her and eat her flesh.

> Save allow you to get the precious reward of your choice in a list. Not very usefull until you get at least one exemplary of such items as quest rewards (like hero cheese for LIFE stat, or the fruit for MANA stat, both being your main multiplier for max health/mana value).

> Eating will increase both your LIFE and MANA stats accordig to your potential value on thoses. So that might be good or bad depending on that. I would say eating one or two to at least use your starting potential on thoses stats is probably a safe bet.

> You'll need one more sister each time to get the 'Good' reward, ranging from 2 to 15 at maximum. However, killing one reduce the count by one ( and it can go below zero if I remember )
So you might want to focus on killing a few, then focus on saving early and then again on killing once the threshold for the reward grow too big. Don't travel with them though, they are weak as hell and without specific training, will get murder by about anything. Capture and talk to them, and send them to town where you can take them to the garden when you need it.