First match only.
I found myself paying more attention to the Marth player than you lol. Tell him to stop countering into your charged F-smashes, it's pathetic. Also, tell him to learn how to gimp Ike. He sucks at it.
Anyways, on your end, against Marth, use more spaced F-airs. He could have punished you a few times, but didn't. He did a dolphin slash when you jab canceled, but you got nothing out of it. You did a good job baiting it, and judging by his skill level, you should do it more often on him until he learns his lesson. Then you can jab cancel and up tilt for a kill.
The F-smash kills were good, but you really shouldn't rely on those. A good player doesn't air dodge or jump into an f-smash after getting thrown off stage.
2nd Match, you whiffed the D-air spike to start, and if he had sweet spotted the edge, you would have been dead. Bad way to start the match for both people. Shortly after, you QD back onto stage, right into him, leaving yourself exposed. Marth is quick and can hit you fast, so he can instantly hit you with something.
Try to refrain from damaging him with aether, any smart Marth player can Di properly and Dolphin Slash you.
At :48, random Up-air? Trying to make a hard read? I don't know what you were trying to do there.
:55, you didn't see the Lava coming and got punished.
1:00, up throw? Okay...
1:03, missing the edge grab? That's obviously not cause of wifi is it? Still, that's 10 damage on you either way. On top of that, he had a chance to kill you, cause you popped up straight to him.
1:30, you missed the edge with aether. I don't know if you were trying to slide back by pushing your aether forward enough, but regardless, it got you killed.
*Any time you throw him and he jumps back into you like a *******, tell him to stop doing that.
1:55: He gets hit by the lava, perfect time to do an up-air or f-air to kill him, but you're busy doing a random drop down b-air. On top of that, you get hit by the lava cause of it. Dude, you seriously have no stage presence on Brinstar.
2:05: OMG, what is wrong with this guy? Shortly after that, poorly spaced F-air by you. After he reads your air dodge, and n-airs you onto the left platform, you gotta tech that. A little bit after that, you tried to grab Marth after you shielded his f-air? Okay...That whole sequence is just bad on both of you. Finally, trying to up-air him after aethering onto the edge is cool and all, but it won't work against a good marth who knows how to gimp Ike.
2:35, you try to grab after he does an initial dancing blade strike. Really, you sholdn't even be bother trying to grab him.
That QD maneuver shortly after was dumb. You're lucky he didn't know what to do about it.
3:09, poorly spaced N-air, leads to dolphin slash kill. You should be aware he's trying to kill you, and one of Marth's favorite killing moves is Dolphin Slash.
3:28, poor use of aether.
Sequence after that, whenever you get hit by him, you're air dodging into him, leading to more hits. Try to get yourself away from the onslaught.
At the end, dumb use of aether, he finally did something about it.
So overall, cut out the constant aethering and don't rely too much on those people jumping into your smash attacks. Space a bit better, and don't air dodge into your opponent as much. As far as match 2 goes, you didn't use the stage that well. You shoulda taken advantage of the slides Ike has with aether, the hit box lag the pods, and be aware of the lava level.
And tell your Marth buddy to learn how to gimp Ike.