Veigar (possible) buff

I have been thinking about a possible "buff" to Veigar (to compensate the E's nerf). Could Veigar's Q's passive count as assist too? (AP assist bonus in last 3 seconds: 1/1/1/1/1). I'm sugesting this 'cause I found so many players that steal my kills and my Q's passive doesn't stack. By the way, could Veigar get a "buff icon" of is stacks? (like Nasus' Q)

Now, his W could have the delay time to 1.05 seconds (live is 1.2 seconds) and a new thing, targets damaged by the Dark Matter could have slow 20%/35%/50%/65%/80% decaying rapidly over time

PS: coment new ideias, so I can edit, thank you :)