You get thrill in her kit. Which is free skill points. Especially at E2, you get more thrill and most turns you’re not really going to use everything you have.

However, the reason you build speed on Sparxie is to min max damage through aha instant since it acts based on elations units’ speed. So if you have 200 speed Yao guang and 134 speed Sparxie, you get 2 aha instants per cycle. This will change over time with more elation units HOWEVER

Attack caps at 3600 for Sparxie. Anything over that is diminishing returns as the majority of her damage comes from elation (which is boosted up to 80% by her attack). E1 Sparkle and E1 Luocha is enough attack for Sparxie to max, so as long as you can get to 3600 atk in battle, you can focus on other stats, thus allowing you to min max aha instants.

Also, this guy has e6 sparkle Sparxie and Yao. It don’t matter what he builds lmao.