The Ravens and The One who cursed Amumu

I thought they were more symbolic than anything, crows are an easy stand in for "Death/Sadness". But if they were connected, that's a hell of a well traveled curse, stretching from Ancient Shurima to Noxus of a few decades ago.

Don't forget about Fiddlesticks and his crows.

Also his long-form lore that was accidentally on PBE for a while mentioned that "Chests of coins and riches were piled before him, the offerings of strangely garbed, bowing emissaries." So one could theorize that those emissaries might be connected to his curse.

I just want riot to give us some more hints at least.