Welcome to MADNESS!
Cthulhu inspired campaigns are never sissy campaigns.
Prepare for obscene gore, depraved astral carnality, and the prospect that you are fighting forces so astronomically powerful that a mere sliver of their power would crush your soul and melt your brain into a warm slush that would quickly burst out of all your facial orifices.
...IF you somehow managed to survive this, you would only exist as a doomed shell of a creature, wandering around the world while begging for someone to end your hollow and pathetic existence.
People will die...and perhaps in the most bizarre and unsettling mannerism your feeble worldly mind can conjure up.