then you didn't love veigar before
his abilities are more sluggish and less synergistic than before.
his mana issues have all been eliminated as his base costs were all massively reduced, used to be 150 at rank 1 for his ult and his E (which had a fair but just scaling cost) would take about a third of his pool basically stating 1 or 2 casts max before needing to back.
veigar is a nightmare to play because he can NOT defend himself from initiation, he has to pre load and heavily predict moreso than before (was .25s cast animation now its .75s before effect)
veigar has exactly 2 abilities, Q and R. Q is a debate, lost CD and targeting and damage but gained range. FARMING WAS NOT MADE EASIER (you auto shove wave making use of the double hit passive). R without enemy AP lost its effect on the mid lane giving him a generalist approach, but i would have preferred better scaling with damage caps in place based on champion level. missing health is not for veigar, his damage should be loaded all at once not combo oriented, i shouldn't have to finish with R.
his W base damage was nerfed making it impossible to kill minions without AP backing it, which is alright the scaling is what you want it for, but you'll literally never cast it under tower unless you want to miss all of the wave.
and if you want to solo hit minions you're either being shoved in for playing too far back and you cant auto to last hit without taking too much damage or you're in awkward positions trying to Q off to the side making you an easy gank target.
TLDR- if the enemy plays correctly and is alert, veigar has zero chance at winning in any 1v1 situation. he literally can not do it. you have to bank on your team mates to start the fight and enable you.
not saying that what he offers isn't justified or that hes too weak, hes technically strong on paper. but its not veigar that wins the game, its the team, champion choices, and how well you combo together.