I've finished the game, and I've enjoyed it, but not so much that I want to go back and replay all the other paths.

I'm curious about the other endings, though.

I chose a woman with the cop background as my origin.
I tried all the endings I could, including willingly joining with her, unwillingly joining with her, killing myself and forcing her to let me free (which seemed like the "best" ending?)

Aside from the dragon and Roy Fellows, I let everyone else live. Apparently that caused the muse to give some more trouble (possibly killing the little girl artist??), and the police captain committed (or wanted to commit) suicide. The death of the dragon didn't seem to have any adverse effects (the Bestower mentioned that the chinese restaurant was pretty good now).

I didn't have the power to summon darkness or ice, was that due to something I missed? Also, at the bridge near the end, I wasn't able to get the beam to cross it and I had to call the mer-general (which was weird, because that help didn't involve water in any way)- was there some way I could've done it myself?
Also, I had to leave the Bestower with the geisting ghosts near the end, instead of having them with me. Would there have been some way to bring them with me as well?

You can bring more or less companions through the more or less people you left alive. If you left everyone alive, they can help you on each screen and you can get all companions to the final scene (which triggers an achievement). Likewise, there's another one for having no companion with you, of course this means you killed everyone in each case.

I wonder about all possibilities and combinations in the last sequence. Went through it only once so far.

You have 4 companions, 6 maximal possible summoning abilites and there are 6 + 1 obstacles to overcome (last one being unrelated to your summoning abilities).
So I guess if you killed every supernatural creature in your way, you would not have enough help to get through. Or your companions can help you more than once in this case?

In my case the fire mage could help me twice but at the second time he had to remain behind because he was too tired to go on and had to rest so there is some leeway in case you killed one or two of the supernatural threats during the rest of the game but not much.

Thx for the reply.

I also did some testing on my second playthrough and now think that you cannot fail on your way to the final confrontation, no matter how hard you try.

My conclusions so far:
1. In case you do not have necessary supernatural aid, Eli and Mandana are able to help you twice.
2. No matter how you resolve conflict in Brooklyn, you still can call upon art (didn't try to force Calli to take her power back though).
3. Logan and Vicky help you once in two last encounters.
Which make a total of 2x2 + 1 + 2 = 7. So you reach the top of the building in any case.