Veigar isn't unviable. Tbh, after all the buffs they gave him, i'd be hesitant too to give him more buffs before people have adjusted, and tbh i don't think Veigar is in all that bad a spot anyway.With the way his rework turned out, and the way Riot wants him to go to keep him healthy, further buffs to his stun's reliability would make him OP. Before the changes, Vivi needed to stun on point partially because of his short range, but now that he has a rather long area of influence, Its a lot easier for him to poke, farm, and even just function at a distance. Sure assassins can still jump his bones and kill him, but they do that to every mage. Veigar has too much damage for them to allot him extra utility, and too much utility to allow him more damage.