When players are banned, their accumulated points are removed therefore affecting their Alliance's total Souls, Damage Points, or VP earned. The process of removing the earned points can affect an Alliance's rank during the Season or Event which is the reason why some Alliances drop or sometimes move up the ranks.
This is the same when a player decides to leave the Alliance while the event is still ongoing or if it's still in the finalization stage. Any points contributed to the Alliance's progress will be forfeited once they drop out of their team.
As always, we strongly encourage all our players to never use cheats or hacks to get ahead in the game or to only leave their Alliance once they already receive their rewards.