That matchup is hella rough since he hits as hard as us yet has way more mobility and range. You have to respect his reach like the other swordies, but do note that all his moves are much bigger commitments than other sword characters, so punishing whiffed attacks is much more feasible. When he's in the air though you actually don't have to respect him that much, since nair is pretty much the only aerial he'll be using in neutral, everything else is for punishing. Since his nair starts from above him you can anti-air him with well timed uairs or up angled ftilt. You can't do this on reaction to the nair though, so you'll have to be making a read here and if the Ike catches on then he can start mixing it up with say tomahawk grab or double jump dair, so of course you'll have to mix up your responses as well (double jump/wavedash back > whiff punish). You can also crouch cancel the strong hit of the nair until around 55% or so.
Quick Draw is something they'll of course be using a ton, quoting this from another thread on it.
I just realized though that since he'll be jump cancelling the grab it'll be frame 8 cause you gotta spend at least one frame in jumpsquat, derp.
As for edgeguarding, uhhh........good luck lmao. I don't have much of a clue of how to deal with his upB, it's hella hard. He's vulnerable when jumping up to the sword, but that's super quick so it's very difficult to be in a position to catch him there. I suppose you could try yolo run off bair? Probably a bad idea. Note that it's a while before he can grab ledge though, he has to wait till he stops spinning around the apex of Aether before he can, so maybe you hit him there, but you'll probably just get hit first. Invincible aerials from the ledge is likely the only good option here.
The Quick Draw is much easier to edgeguard against if he's just straight trying to get back from it, just go out and hit him. If you're a ways off from the ledge then he'll just die if he uses the Quick Draw attack, so he's pretty much boned. But they generally won't go for this since it's a lot more vulnerable. Sometimes you can intercept the walljump attempt if they don't go too low.
Lastly I'd suggest watching Kage vs Ally. Kage loses, but he still puts up a good fight and I mean it's Kage, it's worth watching lol. They've played at
McSmashter and
Lan ETS.
Hope this helps. It's tough, but definitely doable.