Originally Posted by
Horus-2545
I think you are doing fine, honestly. Avoid impulsive purchases. I'd really save up FC for an Assassin Gambler Eddie and/or a Killer Prime (sentinel). Along with a Magus Lilith (but you can usually get her from event Lilith fragments). Those are what I consider great characters for breaking through a lot of those levels. (Along with Iron Eddie and the Purple Demon Spawn). Horus can also be very helpful.
But I really think these things just take time. Enjoy this part of the game and no need to rush. Save your resources and spend them during events. I think at this point I would work on getting nice Talisman (and you can get some good ones from the Trooper Store and from the Arena Store. I think it is best to sometimes ignore events that are too hard. There is so much out there that you can get by just playing the game regularly, rather than spending your resources in a lot of the events.