How do I beat him?

[Goldschuss]

So I have a friend who mains the Mii-Gunner and I'm not a bad player in General, but the Mii-Gunner makes me all crazy cause I can't find a good way to knock him off stage.

He pokes everything with his superior range and if I try to get close to him, he just C-Sticks in any direction which apparently cannot be dogded since its not a single attack, but rather a whole load of attacks still hitting me after the dodge is done.

I'd really like to link an example video but I don't have enough posts to do so.
Look up on youtube "GODOF0LD" and watch the GOG vs DMS Series

 

[AEMehr]

Well most topics of this stature generally go into the board of the character you use. Which I guess would be Falco, judging from your main bar.
You should probably ask the question in the match up thread, you'd probably even get more responses there. Not sure if many people would share problems with their characters here or something like that.
It'd probably be better if you shared what specials your friend uses for their Gunner, since it does change how you should go about fighting any Mii Fighter a fair bit. If your main problem is dealing with their Smash attacks, my only advice to give is to either just absorb the damage by holding shield or roll away from your foe when they use Up or Down Smash (since they can cover both sides) and towards them when they use the Forward Smash. Spot dodging will generally end up having you get hit since the attacks linger for awhile.

As for dealing with knocking them off the stage, I guess you'd have to ask fellow Falco players for that one.

 

[Goldschuss]

I was a falco main, I switched to Quajutsu for a while. And thank you, I'm going to post later in the correct section

 

[AEMehr]

Coolio, then you should head over to his matchup thread. I'm no good with Quajutsu / Greninja so you're better off asking there for sure. So the only other advice I could give you is to play online with anyone since there'll be no gunners there guaranteed.

Since you're gonna find your answer there, I hope you don't mind me locking the topic.