I feel like a champ can stand still and Xerath would still miss his ult...
The point I want to make is that the ult is highly unreliable. It really takes away the fun in using it if you miss like 80% of your shots. Even after Rylies was nerfed, Riot never buffed any champs that needed it putting Xerath in a terrible position. Artillery mages like Lux will just out shine him with a very spammable reliable ult.
I think Xerath could use some love....
What do you think?