So far, besides there being factions, nothing special has been done with them. I think GBX should have some sort of bonus when everybody plays as the same faction (such as a faction pack for everyone) or when everybody plays as a different faction (maybe a rare or epic pack for everyone).
Also maybe add something in the gameplay, such as giving bonuses depending on which factions are being represented and amplifying the bonuses when more there are more characters of the faction. For example, If there is one character of each faction, you would gain a 5% bonus to movement speed, maximum health, health regen, skill damage, and skill cooldown (5% + 5% + 5% + 5% + 5% + 5% = 25%). If you had 2 Jennerit, 2 Eldrid, and 1 peacekeeper, you would gain a 15% bonus to health regen, a 15% bonus to maximum healh, and a 5% bonus to skill damage (5% + 10% for the Eldrid, 5% + 10% for the Jennerit, and 5% for the Peacekeeper). If you had 5 Jennerit characters, you would gain a 75% bonus to maximum health (5% + 10% + 15% + 20% + 25% = 75%). *the percentages are just examples
They should also add at least one game mode based on factions. I was thinking a tag-team last-man-standing type game with 5 bases in a pentagon formation with a central arena, and minions moving along two paths going towards your neighbouring opponents. Your faction would be eliminated if an enemy faction captured a capture point in front of your base, at which point you would be sent and restricted to the central arena where it will become a free-for-all and you try to get as many player kills as you can before one of the factions finishes the game.
These are just my ideas and are open to any suggestions or modifications you guys have.
Sorry for the long post