I disagree. The characters you list are all easily acquired via Selectors and/or Story Mission farming.
The *only* way to get Emma's x-genes is to buy them with crystals. Paywall characters of all types are excellent candidates for a uniform upgrade tickets.
Emma's uni is high-end. Between the base 15% bonus to Attack & Defense, the active buff removal is HUGE.
Active buff removal is just that: It removes active buffs from opponents. Got a skill that, say, increases Attack by 20%? Active buff removal will remove it. Damage Immunity or Invincibility? Not any more.
Clearly this will be most useful in TL (against pretty much everyone, assuming you can target them), but it has applications in PvE as well.
Thanks, I tried out Emma in some friendly matches last night and she's better than I expected. Her ability to shrug off some dangerous attacks from the enemies is impressive. I'll pay more attention to the buff removal next time I try her out. I'm a bit reticent to commit her to an ITGB obe instead of double mind + dmg proc for WBU though. I certainly don't regret T2ing her.
I used my mythic upgrade on Killmonger uni, I still have one extra that I’m saving for a rainy day. If a totally OP paywall character comes along with an awesome uni, or a decent paywall uni has a CTP bonus attached to it, I’ll be ready for it.