Currently there are 5 leaders that can be used,sakura swordman, nightmare hunter, lihht paladin soul reaper and spirirt healer.
How to get new leader in illusion connect
To get a new leader, you need a shard. Shard can be obtained from collapse dream chapter (3 star All stages)
Collapse dream 6 Nightmare Hunter
Collapse dream 9 Light Paladin
Collapse dream 14 Soul reaper
Collapse dream 16 Spirit healer