Relic shield / Targon / FotM / EotE

Could we please give these items a karthus ult active that targets random minions across the map based on the amount of charges, perhaps then it doesn't feel so useless after the laning phase ends :>

On a more serious note, is it supposed to consume charges on void minions spawned from ZZ'rot? They don't give any gold to you or the ally but you do lose charges, hear the sound, and see the healing effect trigger.