Legion had used the Sever divine ability on the blood limb, so it was able to easily pierce the incredible defense of the psychic shrieker.
This success didn't come for free. It cost them some spiritual energy to do so, but they are not lacking in spiritual energy.
The blood limb entered the body of the psychic shrieker and began cutting it up from within while simultaneously consuming its blood to grow stronger.
Legion used the Bleed divine ability too so that the blood of the psychic shrieker would flow easily. This allowed the blood limb to engorge itself easily.
The blood limb was like a blood leech. It sucked and sucked while growing bigger and stronger. All the damage it was causing to the psychic shrieker's body also affected their mental battle.
The psychic shrieker could ignore the pain, but it required mental focus in order to do so. It dearly needed its mental focus for the mental battle, so the extra stress was causing it to falter.
