I'm hesitating between Amistr and Lif. The 2 have ultimate skills which don't decrease intimacy points. Since I only play casually, I like that.
Lif over vanil in terms of int because of her ulimate skill.
I'd go either :
Amistr => Dieter or Eleanor
Lif => Beyeri / Eira
As for the 5th one (Sera), it doesn't really matter which one I choose.
Amistr or Lif?
Bear in mind that the skills still have a cooldown. So at best, Mental Charge and Bloodlust have a 25% duty cycle.
Also, has anyone tested whether Accel Flight is still bugged post Homun S? They probably didn't fix it, but should be checked.
Lif -> Eira is not a bad choice for an Eira, but the problem is you'll lack an attack skill that instant casts like a Vani has. Unfortunately sak doesn't have the cooldown change, so I don't know how much damage mental charge adds.
Lif -> Bayeri? That works as well, but same problem. Stahl Horn has a cast time (all fixed at lvl 5 too, and can be interrupted), and is atk based - your attack will be poor with a lif won't it? I think Vani->Bayeri is a better choice (high matk, and an instant cast attack skill)
Amistr -> Deiter is a no-go, you need an offensive skill. Vani or Filer to make a Dieter.
Amistr -> Eleanor sounds solid - though the cycle-time between bloodlust-on and bloodlust-off is kinda long. I'm planning to use a Filir to make an eleanor, since you can keep flitting up for a much larger % of the time (100%-33%, vs 25% for bloodlust).
Another thing in favor of Vani's and Filirs - you only have to loyal them once, because their loyalty skills (self destruct and SBR) are loyalty eating abominations and of no practical use - so you don't need to get them, and hence only need to loyal them once, and hence get a Homun S in half the time than if you had a lif or amistr, and hence had to get the loyalty skill (since that's the main attraction of those two homuns).
I'd do Lif for an Eira (assuming mental charge adds the damage you'd think it would).
I'd do Filir or Amistr for an Eleanor (Flitting 1 on in the background full time, since it's the most SP efficient option and Eleanor gets poor SP, or cyclic use of bloodlust).
I'd do Vani or Filir for a Dieter, because he needs an attack skill. You're then debating whether to get Vani (for ranged attack) or Filir (for an atk-based
skill, which will be endowable and damage-boost-able by Pyroclastic later on, plus flitting to improve aspd and damage with normal attacks and Lava Slide).
I'd do Filir for Sera, I think, to get Flitting to boost needle damage, and for an instant cast (ie, non-interruptable) offensive skill. One can argue on this.
I'd do Vani or Filir for Bayeri, or maybe Amistr (I think the higher duty cycle of Flitting makes it a better choice in most cases than Bloodlust, and it comes with Moonlight, which would give Bay an instant attack. Vani ofc would have an instant _and_ ranged attack, as well as better matk for Hailage Star).