Shinji

When he wakes up he finds himself confined to a bed with Sakura sitting next to him and rider is in the background. He says, "You made a promise that if I was that cruel during the tournament."

She says, "No the deal was that you had to win and be cruel. You did not win bro, but I did make a deal with grandpa for the next generation if you lost. He leaves us alone."

He scans his body and notices more that three command seals. Sakura says, "Rider is still your servant but now she feeds on her masters sexual desires."

Shinji orders her to release him, rider refuses the order. One of the seals disappears briefly and it reappears with a new command seal on his dick."

Sakura says, "My dear brother, she has power to disobey unless is sexual gratification. But every time you give her order that is not meant to increase your sexual desire. The seal will disappear briefly but will reappear and an additional seal is placed on your body. But if your order is sexual in nature then it merely disappears briefly and reappears with no additional seal."

She then says, "I did make deal with her to control you. Can you guess what the deal is."