Marisa.

Huh?

"The Insect's Threat Continues" Attacking both humans and supernatural beings alike, they are covering the whole Gensoukyou in fear of their spells and magic bombs....

In this emergency situation, the Hakurei's Shrine Maiden's whereabouts are still unknown.... There are even theories that she is dead.

It says.

Are you fine with this?

Wow, that's no good then. The world is in trouble~!

Well, later then. I'm just gonna go outside for a bit.

So is this a kind of enemy that Reimu can't do anything about?

I'm not going to collect her ashes anytime soon, if that's what you're asking.