Well I'm not sure if Yukari + Yuyuko + Remilia + Eirin can handle this.
HA! Yukari could take them all by herself. Those lightweights don't have a thing on the undisputed most powerful Youkai in all of Gensokyo. The only one who can beat Yukari is Shikieiki who would beat down these scrubs even worse.
I love how the first Extra stage bosses of each generation are fighting in the background. SoEW had Evil eye Sigma as the Extra boss vs Flandre from EotSD's Extra