To put it simply, "a fake Mary Sue was deceived by a real Mary Sue into a world full of collapse and became a fake Servant. He summoned a fake anti-Soviet + fake fujoshi but unexpectedly full of cuteness. A real Servant then started BALABALA...
Things to note:
1. Character collapse (To what extent is the collapse? It's almost like the spoof video in Station B...)
2. It may be a bit lily... But believe me this is normal!
3. The heroine is invincible but mentally useless