Reputation

[Nixxe]

Aside from that getting the ranks full for all the Beast Tribes gets you a small new questline, and you can also get material for the lvl 60 relic weapon with the tokens you get from the three highest quests of each tribe (except Ixali I believe)

The Ixali daily Deliverance will give you a moonstone though, which can be used to purchase Crystal Sands for a later part of the chain.