In the meantime I have borrowed someone else's computer. It doesn't run as well, but it can still run Demon okay.
Back to the demas: I figured that they could be fairly flexible because of their stats and resistances. Their cantrip ability also made them considered just to see how much damage they could do.
Another healing Crown, but with Retch and whatever dark ability (ultimately fester touch). I find Retch pretty intriguing thanks to its multiple effects which work even without points investment into cunning. Also, rather than going for a maj. ghoul, I tried firesworn. It gained fire breath and scorching touch, and I also gave it light veil and judge's mien. It proved to be very strong in the early tower! This was one of those runs where some allies had to be revived two or more times, namely the ghoul, vishap, and hob. I'm sure the fly did fine all the time it was around, and the rest were very late recruits.
This was a peculiar Heart run, because I decided to try to build what an "Icy Heart" might look like. Its abilities were icy grasp, cold embrace, sentinel's cry, ritualist, tormentor, frostbite, frozen heart, and icy armor. Most were acquired through transpose soul. Several abilities were swapped, including storm call, absolution, and deep chill. This character's stats were nearly "balanced" between magic, vitality, and agility.
This was probably one of my frustrating victory runs, to be honest. Here and there most of my party had been wiped, including highly reliable healers. Even then, in spite of all the troubles for this run, I did manage to make it to the victory portal. I even cleared out the last two floors, which would include defeating Valindra for the first time in a while! I had to rely using Baphomet and an incubus to do that.
At the right times (e.g. mostly when there are no panic-inducing enemies around), the passives combination could let Cold Embrace be spammed onto whomever. Frostbite seems a little bit weaker to me since its change, but there were some situations that I figure it helped. I have also figured that frost armor is pretty good too; it's definitely a subtle defense boost, but on top of a generic defense buff my character wasn't taking too much damage in quite a few different situations. After all, this character ended up spending a fair amount of time on the front lines, which is pretty unusual for a Heart.
In spite of being almost entirely focused on being icy throughout most of the Tower, I think this character was OK in most situations, but because of poor party management there weren't that many cool synergies (like the use of winterkill or maybe just putting winterlord on everyone). After all, the default Faithful Heart abilities are usually about supporting the party in some way rather than trying to be the main damage dealer. I guess making it to the end is something for figuring out how to play a build centered around Cold Embrace. Even if I have quite a few victories, I figure that there are still many subtle tricks I've yet to uncover, and this is before a new major update that will add a new element.
These two runs weren't back-to-back, but there was only about nine failures between them. I've yet to begin the next cycle, and I'm not sure what I'll want to try next just yet.