Recently I've been using onoki, and his biggest disadvantage, which imo is lack of immobile in kit can be covered if you are using a ninja, that can immobile. With current roshi meta, his passive also starts to shine, as long as ninjas in your team have impactful standard attack (dmg- sage naruto, any minato, masked man, sn itachi; support- hanzo, kage tsunade, sailor sakura), since every other barrier ninja has a passive, that is strictly related to having barrier up. Unfortunately, mystery doesnt belong to top tier dmg, its mediocre at best but blocking ressurection of dps hidans (which i encounter a lot as well) is very helpful. He really starts to be useful the stronger you get, more complex and well crafted your team becomes.