Suggested by Sonic Stein Blade Joker is a decently strong buddy since he has his dark mode as well as his ice abilities. Still, it won’t be enough to defeat an opponent as experienced as Zanya. Zanya once had 2 ninjas at his disposal but now he can top that by fusing them into a new ninja legend. Stein Blade would probably lose to this guy in 1 on 1 combat so you can imagine how lopsided the fight would be once Zanya calls in all of his other monsters to come and help. Zanya Kisaragi wins.