I was doing alright 'til I hit the crypt

Holy snappin' CRAP!

Kill two corrupted monsters he says.
Suddenly there are 10,000 monsters all way more powerful than me.
Just appearing all over the map.
Is it just me?????

Try leveling up, enter merc, go to weaver, click Cat mission to kill 4 corrupted mobs, enter boss room, find out there are around 12 corrupted elite mobs more powerful than weaver. Not fun.

I believe the devs intend this to be a game where overcoming every single challenge that comes your way on your first try is not possible (barring some very devoted gamers). To that end, it seems that master missions and corrupted areas serve as an optional difficulty spike in exchange for greater potential reward. In simpler terms, I suspect the crypt you ran into was supposed to be too hard to beat unless you had really good gear and/or were over leveled or had a good group.

the crypt (as well as "the den") has a higher area level than the surrounding ones.

cararinas mission probably was to kill the corrupted monsters, revive them and bring them back to her. they're usually very strong compared to other enemies in that area.

once you beat and revived them there are some skelletons popping up from time to time which is meant to work as a detraction for the revived monsters so they don't easily follow you anymore.

if you can't fight these skelletons easily the area is probably still too hard for you.