Trying to find an animation, i could have swore it was called "Twin Spears" or something like that. It involved 2 girls with spears obviously. But they were going to fight this giant dude with like either 4 or 6 arms, any way it cuts to them being defeated then raped by this giant. He ends up killing one of the girls after shoving her spear down her throat and fucking the other girls head into her asshole, ends with the dead girl decapitated and the spear impaled through her body with her head on the end, the other girl now enslaved to the giant.