Why does Sated Devourer work with Yi's passive but not Sheen?
If it only consumes 1 hit of Sheen, then, logically, it shouldn't double Yi's passive. Instead, what it should logically be doing is apply his passive, and then another autoattack, reducing the amount of autoattacks it takes to re-proc the passive. It shouldn't be doubling his passive if it doesn't double any other on-hit attacks. Sated Devourer can either: Make your next attack apply twice, or: The proccing autoattack makes an extra autoattack. In the latter, Yi's passive and Sheen would not hit twice. In the former, since the same autoattack is attacking twice, Yi's passive and Sheen should apply.
There shouldn't be a discrepancy.