If Cassiopeia can't be a poison mage

Can we please have one? I give up trying to get Cassiopeia into a place I can ever enjoy again, obviously it's never going to happen. However, a true poison mage is an archetype we no longer have. If she can't be a poison mage, please make one that isn't toxic (ha.)

Perhaps with one could come better ways to show poison damage, since Cassiopeia's DoTs lacked clarity.