Yuna had managed to help Mercedes unblock her channels by transferring her energy through her channels. That was to gently widen her channels without damaging her. If Mercedes did it herself, she would damage her channels because she wouldn't be able to control the flow of magic.

Once that is done, she should be able to maintain a defense spell.

" There," Yuna said, removing her hand from Mercedes's back.

" You should try that spell again. Let's see if we have ...