The whole end-game in Diablo Immortal revolves around trying to become the “Immortals” and last as long as possible as them before you are eventually overthrown by the shadows.
We at Aftershock United Prime won the first round and became Immortals and I can tell all of you now, that as it stands being an Immortal is NOT worth it.
Blizzard have designed it so badly that in order to gain the items from the vault or increase your badge power or to do anything, it requires contribution, this is NOT ONLY uncapped which is a problem in itself but you can keep acquire it through bad means.
Defending the Vault is the BIGGEST reason why I recommend staying a shadow and I will actively be asking us not to go for Immortal again until Blizzard fixes