Ever since that very first trailer of Smash 4 with Villager, Mega Man, and another one with WFT, I felt that I would stick to my main since 64:

. I saw newcomer after newcomer in every Smash 4 trailer and I felt something, a feeling of resignation as this was the first that I was ever conflicted on having a main in Smash before.
Eventually I finally got the demo and tried out the five for it:





. After three days my playstyle completely changed and favored

out of all of them. At that point I was sure he was going to be my main when I got the full game. It was then that my mains and secondaries were all completely unexpected.
Mains: I tried out everyone in the cast this time around instead of my usual "go-to-Mario" mentality in the past games. After unlocking everyone I tested them all one by one in a few offline matches, naturally finding some that clicked and some that didn't. In the end I ended up with two mains.

: The biggest surprise to me but I feel that he fits my playstyle to have as many tools available for any situation. At first I was gonna drop him when testing everyone out since I felt he was sluggish and that the Monado Arts were unnecessarily complex. The revelation kicked in when I learned how to manage his system and declared to myself that, for good and bad times, I'm sticking with Shulk as my definite main for Smash 4. Of course he was a primarily defensive character so I needed someone to round him out, and who else than...

: My favorite newcomer that became VERY easy to pick up and play. As a rushdown offensive character I felt he complimented Shulk quite well. Unlike Monado Boy I had to learn quick approaches and jabs instead of having it easy for me. It's also the most satisfying thing landing a KO Punch on someone and have them sent flying through the roof.
Secondaries: Even though Shulk and Little Mac take care of each other's weaknesses pretty well, I figured I should nab secondaries to practice using a pure swordsman (Vanilla Shulk) and proper spacing (Little Mac). At the moment I came up with one for each of the two.

: To be honest I would've gone with my regular swordsman main, Link, with this but felt the FE characters were more appropriate because the sword is their only weapon. I chose Lucina for two reasons: I wanted to have a female in my roster for the sake of gender variety and her design made her similar to, and simpler than, Marth. She just flowed naturally and her quick tilts and aerials immediately translated to Shulk and made him even better to play.

: I actually started playing her more often and felt that having two fighters at once relieves spacing issues and allows me to plan ahead more often in the heat of the battlefield. Despite her supposed complexity RosaLuma was actually quite simple: Manage your two fighters wisely and play a bit defensively if Luma gets knocked out. She's also a nice fighter to punish mistakes, something that Mac absolutely goes over.
I still play other characters for casual play from time to time but I stuck to these four after about a week of playing.