Game 1: You actually didn't do that bad and I think it was a mixture of that guy playing kind of badly too, he seemed like he didn't really know how to fight versus Ike and really rarely did he charge his FLUDD at all. On the other hand the biggest thing I noticed is your edge-guards. You seemed a little to hopeful of this guy messing up his recoveries and did Forward Smash even though he technically wasn't in an angle to even land on top of the stage and could just slide up on the BF wall and sweetspot the ledge, I would say the same for Eruption too and how reliant you were on it. A few times you could've simply just gone for ledge trump to Back Air instead of F-Smash and then there were times when the Up B hit you through the ledge and it interrupted your Erruption, IIRC it's kind of a distance specific thing too as to whether or not it will hit through so it's kind of more of knowing when if the Up B will interrupt you and just remembering that you can just wait on stage and read the enemy's get-up option.
Another minor thing I noticed was that nice little string you did in the beginning with the Down Tilt to Forward Airs but by the third time the guy actually blocked it and punished you for it. I just think that was at the point where you should've just mixed it up cause it was kind of like the "fool me once, shame on you; fool me twice, shame on me" type of deal. Of course it's kind of hard to think about that in a real match though but I just find it necessary to point out the little things as well.
Game 2: If I recall correctly Down Tilt -> Forward Air doesn't work from like 0 - 25%. You got the Down Tilt twice but both times he air dodged it until the third time when he was actually in a percent where the Down Tilt would put him in enough hit stun for Forward Air. Probably at the heat of the moment due to it working on Game 1, you probably forgot that you had platforms to help you pull it off in that first match. IIRC Down Tilt -> B-Air at lower percents.
I noticed you doing that Eruption stuff again on the ledge too when this guy is basically almost always perfect recovering and sweetspotting the ledge, you just gotta ledge trump or get ready to read a get-up. Both in game 1 and game 2 you got a grab at 0% and it seemed like instinctively pummeled for some reason to which they just broke out of it. You should keep in mind of percent based punishes, you were both at 100% on first stock and he was on the ledge and you ran towards him with a Dash Attack, a really obvious option that the guy predicted and punished you for, IIRC he got a Back Throw on the ledge but it didn't kill you because he didn't pummel but he did end up getting you with U-Smash.
Overall second game it seemed you were tilting pretty hard. You Side B-ed into his shield and got punished, you got hit by his Down Throw to Up Smash at high percents by air dodging when you could've just jumped away I'm pretty sure. You kept pummeling at low percents and him breaking out of it, and correct me if I'm wrong but you Forward Threw at low percents instead of going for a Up Throw or Down Throw combo to help you rack up percent but it seemed you desperately wanted to get him off-stage for a potential gimp which it didn't really do much since he was at low percents nor did you take advantage of your stage control when throwing him off.
Overall this match you seemed to be playing pretty recklessly. You're getting hit by a lot of Fireballs like you were playing wifi Mario and couldn't properly power shield. You let him recover for free all the time and never read his get-up options or ledge trumped and you kept trying to do stuff with D-Air (which Up B beat you out every single time) and Eruption which either is timing or simply doesn't work versus a player who can properly sweetspot Mario's Up B which it isn't to hard tbh, his recovery is really good. You kept doing low percent back / forward throws for stage control even though it wasn't doing much for you and you were probably way better off just going for Up Throw / Down Throw to Forward Air to help you get caught up in percents with him (NOT FOR SURE, you were at high percents so rage may have affected it but he was at low percents)
Game 3: You basically were destroying this guy, I could tell this guy was either nervous or pretty new to Mario cause he never does Up Throw -> D-Air -> Forward Air at 0% and always go for D-Throw Up Tilt which you obviously escaped each time. Again for the second time you went for a risky Dash Attack on the ledge which wasn't as obvious as in the second game cause you could have done Dash Grab considering how close his shield was to breaking but you gotta keep in mind either Dash Attack / Grab is spot dodgeable and he only at 55% so he punished your Dash Attack. You could've went for a safe Down Tilt / Forward Tilt poke on his shield to force a reaction instead of going for Dash Attack and putting you in a position right next to him.
For the most part it's the same thing I have to say in terms of edge guarding this game. I could tell on the second stock when you were at really high percents you were choking. You kept doing predictable get-up options which was recovering above him to avoid Up Smash which he read three times and overall he just kept reading all your options and continuously threw you off the stage but luckily this guy didn't pummel enough for Back Throw kills and you barely survived most of the time and eventually got D-Throw kill. I could tell in the end the Mario was REALLY scared though and respecting you.