Aside from having all your quests as 1 hour during the day and 8 hours at night, and challenge towers.
What's the best way to get souls for F2P players?
Finish shao kahn tower, finish daily quests (20 souls per day), reach at least kombatant 1 in FW, tower (even if you lost the fight you have a chance to get souls, now is edenian), and finish single player mode
What do you think?