Each member to sign up individually and join a lane to defeat the other alliance. Think of capture the flag!
You must be furnace level 10 to join. You must also have at least 10 players signed up from your alliance to battle in the championship.
You can change lanes before registration ends and R4/R5 can now switch players around in lanes after registration!
Lanes allow 20 players but you can add more than 20 to them only the strongest players will be used. Divide your alliances members by power rank into the lanes until they are full. Keep an eye on the power level of each lane. If once is much weaker even it out.
Add your weaker players to the end of your lanes that way they still get rewards but don't have to fight!
Example: 60 players in your alliance you break them up by power rank 20/20/20