With nearly every new champ having some form of cc or dash, keeping a fed susan away is harder than it sounds, since every meta jungler has hard cc, most supports do as well, midlaners tend to nuke, and adc's except for ashe really have ways to get away from/keep at bay, except it works for both teams. While susans adc probably doesn't have to rush a qss, the enemy does, putting their adc at a disadvantage midgame, and thats just to avoid a potential wither/cc once that fight, god forbid theres an amumu or an udyr with him (or, grab the ointment now if hes paired with yummy). Thanks to numerous buffs, all it takes is Nasus building his core fudging items to hit 40-45% cdr (based on personal saltiness), then pop his ult during a particularly juicy minion wave unattended in any lane to catch up, and that's on top of the bonus stacks from jungle camps, or a jungler being nice and letting you steal their small chickens while they get the biggun.
Look at this another way: in order for nasus to hit 300 stacks by 20 minutes (which is doable in even bronze pretty averagely), nasus would have to hit 100 q's on normal minions, or 25 cannons/jungle camps/champs, or any combo. Thanks to buffs, you can't really stack armor against him as his e negates %armor, you can't stack attack speed bc you'll eat a fat witherino, damage is cool but unless you have the burst to hit him while he withers and pops biscuits/pots he's gonna heal up with his passive/spirit/possibly lifeline (again, personal saltiness). There are waves every 30 seconds pre 20, meaning 37(8? technically but thats at 20 so), meaning before 20 there's 12 cannons. Assuming you only get the cannon, that's 144 stacks already. If you grab one minion per wave on top of the cannon, that puts you at 255 stacks at 20. If, like most susans, after the first real back at 10 you grab your mandatory 2 cdr items, you're at the point where you're probably going to be getting 4 minions a wave at least, and all the cannons, and the 1 per wave before 10, that puts you at 417 just at 20 on a lackluster q farm and that's _not including any champ/jungle/scuttle/enemy pet/summons stacks either _. You throw in that even at challenger level they'll forget to keep a wave in check and suddenly after 20 you're looking at a possible 48 stacks per minute per lane, and if you have a susan who is metagaming the fuck out of his team stacking multiple lanes as they pile up, it's gonna be bad.
Veigar isn't as big of a problem imo, mainly bc shutting him out early pretty much keeps him out (unless your team eats his stun at an inopportune time, but that +5 per assist gets nasty quick if he hits stuns (or buys, idk, an item that puts out a shield to his team giving him an assist on everything regardless of skill), and with his being a flat ap gain it's even more problematic. Veigar bottom is really the only time I've seen it be a huge problem, because with a skilled leona/thresh/lockdown champ, someone's gonna be cc'd for a while and hit with guarenteed w's, chunking them super hard.
Although junglers make a huge difference vs both those champs, Nasus is one that it really doesn't matter if you do or not. Someone that plays him and has watched any big nasus player will tell you that there is always a way to farm safely enough, and if you're garnering jungle attention, it means that your jungler should be pressuring the shit out of objectives/enemy camps/ other lanes and snowballing them, as nasus will pretty much stay relevant regardless
is a bit more annoying because he outscales you by landing his abilities and farming. You put him behind and he'll slowly outscale you poking you and other people. I don't enjoy having to tail them all game and stop everything else in fear that in the minute I'm gone they'll grow stronger than me. You basically get locked into your lane as an abusive baby sitter :l
and we all know she has matchups that will stop her in her tracks.
