Okay, so Kemious and I were having this discussion in chat a bit, as to why RFA should only trigger the SP penalty if the unit is base level 5 or higher (AKA veteran folrart paladin/equivalent and onward).
Basically, the idea is that the costs to use that SS aren't just in the SP price of the grim and the SP penalty afterwards, but the cost of not using the set phase to play another, generally useful unit, as well as the fact that you're not using an SS that can do something else, maybe even better (against a rush), such as Rasam or Diondora.
Essentially, my argument is as follows:
The set phase has some SP-equivalent value. For instance, if you have 10 SP, you can't drop 3 level 3s in one turn. For bigs, that's not such a big issue. For rushes, not dropping a unit is a pretty big issue. IE, if I'm playing a miracle fruit in my Gowen rush, I'm not taking that turn to drop Belltia, for example. So the opportunity cost of that set phase, spent playing miracle fruit, is greater than 0 SP. We pegged it at 1 SP.
Next, you obviously have the SP cost of a grim (which you don't get back) if you're setting up RFA or an engage-removal SS, or at the least, an SP lock if you're playing a great spirit for agility manipulation SSs. In RFA's case, this is 1. And even if regular Prim raised all levels by 3, if you view SP lock at say, 25% of the value of a unit's SP cost (because there is some opportunity cost to having Allind sit on the field instead of dead and giving you your SP back for Gowen grimspam), there's some SP cost in that. So let's just put that at 1 SP.
Next, you have to keep in mind that you're using a removal SS in that slot, and not some other SS that could be beneficial for you. For instance, if you're using 2 RFAs, what you're *not* using is, say, Chamail->SK2 SS (or Olvaus SS). Or Diondora and Rasam SSs, such as in Worthing's Gowen rush file. Those other SSs have a certain value to them. For instance, knight of the 2nd shrine SS can be compared to fairy dance SS (and often times is better). If you compare Rasam SS to the single-target (or even multitarget engage grims), her SP equivalent value is through the roof. EG if there was a Falkow grim that stated "engage two target enemy units until the end of next turn", how much would it cost? I'd wager 3 SP at least. (Not saying to nerf it though =P). Diondora's SS is a flanking attack combined with 40 damage. So it's at least a 2 SP value.
So basically, the opportunity cost of not using Rasam/Diondora/Zalzagul/Gafc/other tier 1 SS is 2 SP.
So, when all is said and done, why are removal SSs so bad against rushes?
Set phase cost: 1 SP.
Playing whatever it is during that set phase to set up the SS: 1 SP.
SS slot value: 2 SP.
Now this is before we even factor in the -SP next turn of the SSs themselves. For Raste/Metia/Ladol/Bastandora, this is -2. For RFA, this is -1. For deep squid and Nereis, this is -1. Thankfully, for Miandela and Astaforse, the testing team didn't lose their minds yet, and they're still at 0.
So, let's do some scenarios:
Needing to trigger Nereis/Deep squid is basically a 4 SP endeavor always. 1 SP set phase, 1 SP spent on setting the unit (you get it back at the cost of LP, but the immediate hit is to your SP), and a 2 SP SS value. Needing to fruit to hit RFA is a 4-5 SP value, depending on if you have the Gowen sphere or not. Of course, this is also under the assumption in the case of Nereis/Deep squid that you're playing Falkow and already have the spheres for undine/sylph.
Double RFA: if you need to sphere up, this is currently an 8 SP endeavor. 2 SP to set the fruit, 2x2 SP SS slots, and -1 SP x2. If you don't need to trigger it, it's a 3 SP value in each case (meaning you return a level 5)
Set 6 non-Lawt agi SSs: if you have to trigger these, they're a 6 SP value when all is said and done. If you don't need to trigger them manually, 4 SP.
So then why do some files use these SSs? Because some files actually manage to mitigate the costs ahead of time. For instance, Lawtia can abuse sin SSs because it doesn't play units specifically to be sin fodder. Rats and succubi have amazing opens, which are far better than a great spirit can be in the case of EN. Next, Falkow can use the agility manipulation SSs first and foremost because it already has the sphere to trigger the great spirits, and also because Falkow, being, well, *Falkow*, already has access to returns and tidals so that it can efficiently deal with rushes.
This is why it's generally extremely stupid for Lawtia rushes to use removal SSs outside of EN, unless we're talking about Belfyna dolls, to use assassin to conserve LP--namely because landing an exchange of souls for 3 SP will generally net you about as much of an SP advantage as hitting a sin SS, when all is said and done, the only issue being that the Lawtia player has to predict when his opponent will leave SP floating in the open phase. Also, a Lawtia player can set up the death's embrace+bitter destiny combo, which also can provide a greater SP advantage than hitting a removal SS.
Mostly though, it's basically the idea that if not for the existence of units that are "all eggs in one basket" types of units, removal SSs would be downright stupid to play. The only time that removal SSs are better than a Diondora SS, IMO, is when the opponent controls a single unit. But that happens readily enough.
Of course, another drawback (especially to the set 6 agility SSs) is that they can backfire very easily if your opponent uses unwanted charity (or now sweet dreams), which is why Nereis or Deep Squid will forever be recommendations in my book over Raste/Metia/Ladol/Bastandora.
So what does this mean?
IMO, removal SSs need to be changed. Yes, they provide a massive advantage vs. bigs, but outside of that realm, they're very lackluster, and due to the fact that there are far better SSs to use vs. tribal rushes, which Alteil seems to be balancing towards, since I feel that everyone and their dog wants some sort of pet tribe to be viable. With Callonia, he wants to **** solar kingdom forever and ever and anyone who uses returns is a cheater. Peralisc and Fargone hate returns in general. Angelspawns wants TGC to be viable. I myself am partial to WK and Merc nation (but concede that merc nation will always suck since it can only do one thing well, which is to hit you at mediocre agility).
So yeah, this is basically a public service announcement that unless you really, really hate bigs, that your best bet isn't to use removal SSs, but go for more generally useful SSs (Rasam!). Furthermore, if you have some sort of cheap, anti-big tech in your file, you don't even need these things at all.
In the meantime, if the testing team wants Gowen rush-type strategies (big red seems to have found a new home with a Refess base for flames of judgment) to see play again, remove the -1 SP from RFA's SS, put a Gowen level condition on Miracle Fruit (Refess has talisman of disruption, Falkow has tidal, Lawtia...not sure why Lawt has nothing yet...maybe a 1 SP that cems 2 level 1s conditional Lawtia 3+?).