I wish buying early MR vs AP assassins meant something, same can be said vs AD assassins

When I play Ryze, the moment I get ahead, whether that be in CS or a kill lead, I always buy early resistances. I know that assassins are innately early game champions but it feels underwhelming coming back to lane with decent resistances that don't provide that much suitability in lane. Sure, I can come to lane with maybe Zhonya's but think it's a bad item on Ryze (if anyone can convince me otherwise) since Ryze requires a ton of movement for him to be effective. I build Adaptive helm sometimes, especially when there is 2 or more AP champions, but it just doesn't do the trick VS AP assassins. Not sure what to do, I am open to suggestions.

Additiionally, Seraph + full resistance item doesn't do that much either. CD are very powerful on assassins.