I suspect it's like the spotlight ones, but even MORE of a slant so when you roll a 4/5/6 heck maybe a 3 it is even MORE likely to be a pierce.
I am under the impression it works the same way as highlighted units, but because it highlights ALL Pierce units instead of 3 specific units, and thus all pierce-types get a boost to summon rate, it is essentially more effective at getting the highlighted unit type than getting a highlighted unit
Thx to RNG-sama.. for these beautiful pierce gacha..
http://prnt.sc/byp2j9
So you took my pull (CC and TL) and then hacked in double Mei Plumblossoms... DARN YOU!!!!
Meh, I still have my Anemone, Flowering Peach and BB (though I'm not fond of BB's design or scene, she still slices up pests with the best of them). On the note of Flowering Peach though... she apparently looks up to Peach even though she's stronger than her lol (6* vs Peach being 5*)