Hello all, new aspiring MK player here. New season in my region and I decided I'd like to switch and use a different character for once. I had a hard time choosing, but in the end I went with MK since he's one of my favorite Nintendo characters in general (I even have quit a few childhood memories of unlocking him in Kirby Air Ride, where I would use him and nothing but him after I got him), I like how he plays in this game, and he seems like he has the opposite playstyle as my main
and would make an ok backup (I say OK because I am aware of his high learning curve and that its going to take time to actually get good with him): Mega Man has a fantastic neutral but weak advantage, Meta Knight has a bad neutral but great advantage. I'm on Day 3 of learning the ropes with him, had some ups and downs so far playing For Glory but I hope to come here to learn a bit more from you guys
. I'm training MK in secret from my buddies and the other tournament people I meet up with, I wanna surprise em when I get the character down and knock em' off their socks. Since he's a hard character to learn, I know its gonna be a long road and not everyone would recommend it, but I think it'll be totally worth it in the end.
On a seperate note, just a little heads up but while I'm none too experienced with MK, I don't think most any of those characters would be a good secondary at all. More than half of the characters you mentioned have a notoriously high learning curve and take quite a lot of time and dedication to master, and usually aren't worth having as a secondary because of tha, especially when MK is already a technical character.
- Fox, Pikachu, Pac-Man and Rosa are good characters but they're all really complicated to get good with and take time to learn.
- As a Greninja user myself, he's really good for the most part (top 15 even imo) but he's very difficult too and I most definitely wouldn't advise having him as a secondary. You'd probably want to master your main first before picking him up or solo main him if you wanted to be really and truly viable with him.
- Ryu is very good and many say he's top tier (a PR member in my region who mains him told me he thinks otherwise tho, unfortunately I forgot to ask why), but he's probably the very antithesis of easy.
- I don't think Kirby's learning curve is too high, but he's kinda 'meh' and I couldn't really see him winning any matchups MK wouldn't already. Correct me if I'm wrong, though
- Shulk is both bad and has a ridiculous learn curve, probably the last one listed that I'd go for, personally. Bad frame data + learning how to manage and make use of his Arts makes for an extremely difficult character and not too great a character at that.
Of the ones listed, ZSS would probably be your best bet. I wouldn't exactly say I think she's easy, but she doesn't require crazy high amounts of in-depth character knowledge like the others and takes requires more general fundamentals to learn than anything else, and she's real good tier-wise. I don't know enough about Ike or Diddy (only because he got nerfed, and I never bothered to study him much after that) tho, so I'll shut up here.
These are all my two cents tho, take it all with a grain of salt.