You complete a quest a collect parts for Cayde and Banshee to build a Exo animal that's indestructible in PvE and can be destroyed in PvP. You would receive Legendary Marks, experience, Vanguard Rep, and either a subclass specific gear or weapons: legendary or exotic. Titans would get a bear or some type of predator feline, Warlock would get a predator bird, and Hunter would get a wolf. Commanding an attack would be like the sword: they would use energy that can be collected as purple ammo. As for what subclass they would be they would either correspond with your subclass or like choosing a sword you would choose their subclass. Titans and Hunters animal would jog along side or when running would follow close behind, as for Warlock's bird they would sit on his/her shoulder or fly behind you. The animals color would primarily be silver with an accent color of their subclass. Let me know your thoughts on this.