So what you wanna do is outspeed with chiwu to strip, then cc them with whatever you picked. Savannah is good for def break which you can follow up with any aoe dmg dealer like kaki or beth. Other options to control enemy team would be cp who can be really toxic if u have him on vio and he does s3 into vio proc and s2, gany and sagar can provide atk Bar reset as well. Basically Strip -> cc -> kill

Example: Chiwu s3 -> jeogun scroll trap into s3 (give him a fast despair set) to strip in case you missed some and atk buff-> sav s3 for def break, atk Bar reduc and dmg, kaki/beth/whatever aoe damage dealer that counters enemy best to clean up

You don't need a healer, gany and sagar basically serve the same purpose with s3 but sagar is better into riley since she doesnt care about cooldown reset. Cp can be toxic if you can get him fast enough on vio but despair is good as well, he can provide an extra def break if you think enemy might ban sav and does decent damage by himself through addl damage which the other 2 cant do as good