Finished, and I have to say...they actually listen! Or at least I feel like they listened, because wow! This was such an improvement from what we've had so far that I don't really have any criticisms about it this time. I do have one complaint, but I'll leave it at the bottom.
Below are the current merges and skills my units have. They're all level 40, so I won't list that.
Leif: +2. Light Brand (+Eff), Repostion, Noontime, Steady Posture 3, Chill Spd 3, Threat. Atk/Res 3, no seal. He was the straggler. Despite having good Spd and Def, he could never hope to match up against many enemies, and it just got worse for him in the later stages. He did manage to wall the occasional attack, and when I finally got Reposition on him he became an invaluable asset for positioning, but he was clearly the least valuable unit on the team.
Finn: +2. Slaying Spear+ (+Eff), Ardent Sacrifice, Ruptured Sky, Atk/Def Solo, Lull Spd/Def, Drive Spd 2, no seal. He was my most offensive unit here, even more so than Reinhardt. He rarely suffered, and was the luckiest unit in terms of RNG. I'd go so far as to say that if I ever get a Finn up to 5*, this build will probably be on my mind. In fact, I did give my Brave!Lucina a Slaying Spear+ a long time ago...hmm, a thought for later.
Reinhardt: +2. Meisterschwert, Rally Up Atk+, Ruptured Sky, Atk/Spd Push 4, Spd/Res Ruse 3, Threat. Atk/Spd 3, Spd Smoke 3. I thought he was going to by my MVP, but I was left surprised. Despite his nice Atk/Def stats and access to Meisterschwert, he was never able to secure kills before he was retaliated upon by pretty much every enemy he faced. This is one time where I'm actually glad I wasted $10 on the FEH Pass, because I had to abuse the rewind mechanic SO hard for him.
By no means did this mean he was a bad unit, though. Once he got Meisterschwert, I steamrolled through some of the early-mid stages with relative ease. A couple times, he came in clutch as the last unit standing. But in terms of overall usefulness, Finn was the clear winner here.
Olwen: +5. Thunderhead (+Eff), Rally Up Res+, Blazing Light, Life and Death 4, Atk Feint 3, Spd Opening 3, Savage Blow 3. Despite having LnD4 for the majority of the playthrough, she never did a lot of damage to non-Blues. Reinhardt had Joint Hone Atk before he got Threat. Atk/Spd 3, and even that didn't do much for her. Though I know her seal will disappear (at least, if I get her with a Forma Soul...which I won't, let's be honest), I do have to say that Savage Blow 3 came in clutch way too many times to count. That little bit of damage was just enough to give me victory in a lot of fights I otherwise would've failed hard.
The units that I'm at least considering using a Forma Soul for are Finn and Reinhardt, most likely Finn. Finn left me highly impressed, and I just know I can make great use of him. Reinhardt on the other hand is a unit I already have at +1, which would make Formhardt +2, and the skills he has right now (except the seal, which would disappear) could potentially make him one of my most valuable units if I could get extra merges on him. In terms of merges, though, Finn is a lot more common than Sword!Reinhardt and would end up being +10'd far more quickly.
In terms of what skills I'll shoot for in the remaining days that I wish the two might have in the end of this round of HoF, so as to make them more likely to choose them? The only thing Finn would need, funny enough, is his default Goad Cavalry. I've been wanting to make a real Horse Emblem team for a long time, and he could be the piece that puzzle needs. For Reinhardt...I'd probably say he needs nothing, but I wouldn't be averse to his Ruse being Spd/Def instead of Spd/Res. It really just depends on what kind of team I'd put him on. He'd probably thrive in a Mixed team, and my Brave!Lucina is more than happy to let new friends join the slaughterhouse. For the other two units (Leif and Olwen), I won't make any suggestions because I wouldn't touch them with a 10-foot pole.
Now for the complaint, which isn't a major one but is still something that annoyed me. The enemies' stats in the later stages got way too bloated. Many of my losses were specifically because I lost battles that I should've won (even with the enemies having "merges"), but didn't win because a random Fir had 77 HP and destroyed Finn in retaliation. It went so far that I had to check the battle forecast every time, and if I saw Idunn in it then I simply went to one of the first stages to give a unit a free skill/merge.
I love that the RNG is finally taking the units' personal strengths more into consideration, while still giving occasional weakness cover-up options. I also love that they have torches as a prize in a lot of the final stages, so people could have more chances to improve upon their units before taking on the next stage. But there are two things I feel that need to be fixed.
1) Units like Idunn that are difficult to eliminate outside of HoF, and NEAR IMPOSSIBLE to damage in HoF's later/latest stages, need to be removed or at least need to show up in early and/or mid stages only. No one likes being dealt a hand they have no chance of winning with (just thinking about Bridal!Marth still makes me angry), but it's even worse when they're shown their enemy's hand and know they have no chance of beating it. I know it's just an oversight, but it low-key makes me feel like IS is taunting us.
2) There needs to be more incentive to merge units. With merges in HoF not transferring to the main game with the Forma Soul, there's not really a lot of incentive to give merges to your units despite how important they are. Perhaps giving you an extra prize based on how much you merged your units combined by the end of the round (capping at a certain amount so you didn't feel awkwardly pressured to sacrifice your skill inheritance) would be a good start? Some feathers would be nice, although I wouldn't say no to a few more Codes either.
Overall, I enjoyed this way more than I expected to. Round 1 was great, but round 2 was disgustingly stressful and round 3 wasn't much better, so it's a great breath of fresh air to know it's not just IS using as an excuse to stall for time for some random new project they have. If they continue to improve like this, Forma Souls may potentially end up a lot more valuable — and also a lot more worthy of purchasing.