Even if you don't have a rainbow girl yet, you will eventually (~5% chance to get a rainbow girl for each 11-pull you do). Just buy the rainbow skillbloom first each month, and stash them away for now. You won't regret it.
i tend to get the hearts for 150 life crystals (100% 2nd affection does spike your stats by a lot), then save up for the skillblooms... mainly the rainbow ones
but if you got girls that can bloom (aka, 2nd evolution), get the petals they need cause they get some major boosts when you advance them.
in fact, everyone should have Evening Primrose and she can bloom. You should at least get her to lv80 Bloomed status cause she's actually quite nice.
besides, when your teams are strong enough, life crystals will pour in from the 80 stam event missions depending on how much you can play them
I haven't been farming them - I'm on 1050 out of the cheap hearts and rainbow bloom - it's true they trickle in nicely
Not sure if the skillblooms are really that worth it for a resource that right now in nutaku is pretty slow to get.
They give you an extra percentage of Skill activation rate and nothing else, but it's really small like 4% or something , i don't remember, but if they were dress blooms instead then i would definitively consider them worth it.
I use Life Crystals to buy petals for blooming since there's at the moment no other way to get them.
For flowering hearts i would use the whale medals.
FKG: 053232470 Strength: 479,458
It's typically more like 2.5% per skillbloom, but you're looking at this the wrong way; it's about the overall increase in DPS or in some cases, even self-healing.
Take a look at the recently bloomable Kerria's skill:
At level 1, it's a 26% chance of triggering, at level 5 it's 36%. This is a jump from a 1:4 chance to proc to a 1:3 which is a 38% increased chance to proc and coupled with the life drain, this is a massive increase in Kerria's overall fighting capability.
And this isn't even taking skill chance trigger buffs from other girls that might be in the squad into account which just makes those numbers even higher. Skillblooms are, enhancement for enhancement, worth more than any other enhancing unit (including dressblooms) which is why they're not typically paywalled.
The only advantage dressblooms have over skillblooms is for increasing TP for units that aren't likely to see combat (i.e. Whaleship).
to add onto that, if you have girls that increase skill chance, then that makes it more worthwhile for the skillblooms...
consider Kerria's lv5 skill with my team's total of 1.6 times skill rate... that takes her 36% chance and makes it 57.6% chance to activate... but if left at lv1, it'd make a 26% chance become 41.6%...
that's quite a noticeable difference...