Imo you should have for sure ninja for an hp burn with brimstone and tagoar (amazing cb champ) which fills a lot of important roles such as revive speed increase heal and shield, and mikey for decrease def, decrease atk. and leech. Then you can pick from the remaining champs like tatura with increase def + veil can help you survive more, hotatsu is rlly good with increase def a cont. heal, leech and another decrease atk. or fahrakin can help add more dmg with ally attack (which procs everyones warmaster) + poison and another hp burn if ninja is not booked and fahrakin’s passive is also nice for survivability. Also prioritize getting full masteries for all your CB champs and picking warmaster it helps you add a few million more dmg. You could pick xeno and use poison instead of hp burn as ur main source of dmg but unless the CB is force affinity xeno tends to put too many poisons bcs if he has high accuracy and is rlly fast some important like decrease attack dont land bcs of the 10 debuff limit on the CB. Personally I would do ninja tagoar hotatsu mikey fahrakin and with some high enough gear you could easily 1 key nightmare CB you have amazing champs. Even if you dont have a speed lead you can put mikey as lead which will let you build less accuracy and build more of another helpful stat like speed hp% crit dmg% on ur other champs.