Veigar has often been at the threshold of being considered overpowered in bot lane, and he's been maintaining enough of a play rate there that it's time to step in. One thing different between bot Veigar and mid Veigar is his scaling nature. In bot, he's actually even more of a snowball champion than in mid where his win rate steadily climbs over game time. So we're blunting that early-mid spike with a cooldown nerf that his mid players aren't as reliant upon and can more easily outscale.