I take each character to the lab for 10m, maybe 15, just do some basic strings, literally mash some, check out specials. I don't look at frame data or anything yet, I just hop around and hit buttons. Then make a mental list of characters who I liked when I did this. Liked the flow or feel of , and I auto add characters that look particularly cool or that I really like thematically. Once I've gone through everyone this way and made the list of characters who catch my eye, I start going through those characters, spending more time in the lab, exploring strings and specials and getting a better overview of that character's tools and how they 'flow'. I try to do a couple poverty, 20m of fiddle time combos , etc. I usually eliminate a lot of the list doing this. Once the second list is paired down, usually to 3-6 characters, I start looking at frame data and what the strings actually do, and start to try and formulate a general idea of what that character's gameplan is, and how good they might be at it/in general. I start checking the forums and youtube at this point as well for tech and general information.. the goal being to trim that 3-6 list down as far as possible. Whoever is left I usually main. Sometimes this leaves me with 2-3 characters. I also consult GENERAL tier list information.. im not exactly a tier whore, but if a character I like is universally considered bad (not just ok , but actively bad) I will usually drop them from the list. Yes, that general consensus could be and sometimes is, quite wrong - but it's also quite often pretty correct. I know how I am mentally and everything, so to me, playing a "good" character is important because it doesn't leave me an excuse or a cop-out. Every L I take , I have to hold with no way to lay the loss on my character just not being great or whatever.
That said, in Inj2 I'm maining Atrocitus right now, because.. deezam. I just don't think he has any real serious weaknesses. He has good answers vs zoning, some of which are extremely potent. Good damage. His trait is super super useful for a ton of different reasons and in s ton of different circumstances. Advancing mids. Huge corner carry. He's got pressure for DAYS and meterless conversions with trait out. Trait also acts as a defensive measure to some degree. He looks pretty cool... He's also like.. Me. Big, broad shoulders dude. I have a terrible temper, I break keyboards and controllers and scream and cuss and ya know, RAGE. I'm also a fan of cats and have four and work with dogs and cats for a living and am involved with local cat charities and all that.. so a big thick super pissed off guy with a cat companion is practically me.
So, as secondary and tertiary characters.. I have GA and Batman. Both of whom I liked from Inj1 a TON. I didn't play i1 in it's heyday but came to the game 6ish months back just to get an idea what i2 may feel like.. and I really liked GA and Bats. GA seems better this time around and Bats may or may not be one of the strongest characters in the game right now.. but for some reason I just didn't want to main a legacy character. Bats is so heavily played I just kinda wanted to do something a little different.. though I'll likely spend time learning Batman off and on. GA is AWESOME but after a couple matches as him I literally feel mentally tired lol. He's so active and dynamic it's great, but he works SO HARD for those wins. Again, just wanted something a little different in my main.
Honorable mentions and characters I will likely visit at some point:
Deadshot. He was a potential main before launch. A character I really liked the look of. He's obviously strong.. we have all seen the threads and experienced it for ourselves I'm sure.. but pewpew zoning, to me, isn't all that fun and so I haven't messed with him much. The almost universal hatred towards the character doesn't bother me, but I honestly feel like learning the game with him wouldn't make me a good Inj player. He would be a crutch. So, shelved.
Canary. Super dope. So swaggy. So smooth and fluid. Just too unsafe for my tastes. So, shelved.
Cheetah. Close eye on her. She's nutso. Shelved mostly because I just don't feel like diving in to her whole heatedly right now. I feel like she's a character that requires that to be successful.
Robin. Dunno. He's awesome, but he's just missing something for me. I feel like he's not all that good. I may be TOTALLY wrong and it's super possible I am.. but I'm not personally confident in the character right now, so, shelved.