Is this some sort of tornado cash derivate? Is there a relayer network and if so how is it operated?
No there is no relayer network, however this feature could be expanded on but relayer in the same sense as tornado cash’s relayer where funds go inside one smart contract and out by another one.
Kusama Shield is a modern shielded pool(smart contract with some zk logic in it), its a smart contract on Kusama Assethub, here is a comparison between the 3 main shielded pools: