i'm gonna give yushun a bit more time to post his own demo. i've watched him a few times and haven't seen much of anything similar to this. yes, it looks fucked up in a few spots, especially in your personal demo. however it also looks like a number of source spec glitches we've seen time and time again, albeit more pronounced. take a look at these players at the following ticks and post your thoughts:

Cyber ibis.a: blue arena, 17500, 21800, 39500, 41800
maynard <ibis>: blue arena, 7400, snap at 12500, 23300. sex fix, 7000.

personally, what i see there is the same exact movements we see on yushun, though a bit more pronounced in most cases. that could be due to rates, ping, lag spikes, anything like that but the movement signatures i'm seeing don't scream aim assist to me, though the snappiness would lead us to believe otherwise. also, his stats are mediocre at best, his headshot % is fairly low, has no history of bans anywhere, no other account could be found for him.