I actually faced a Ryze and it was pretty easy. Because Ryze has to stand still, you get your voidling damage off. Also, his snare doesn't stop you from just ulting him to death. And ofc, silence is OP, Ryze just can't combo unless you miss.
The only issue I find with AD Malz is you really can only take on one (good) URF champion at a time, 2 or more facing you and you do almost nothing, as everyone has some way to interrupt your ult or kill you. He wins pretty much every single 1v1 in existence though, and if they run at you one at a time, you can just wreck them in a line.
Also, I just tried
and god is it OP. You can solo herald, dragon, or baron pretty much anytime after you get it, and heal from 10% to full at the same time. It also helps a lot when your voidlings are bashing on someone while someone else is bashing you.