So, today I logged on after playing with a friend last night that was newer to the game. As I logged on this morning my battle sprite was completely missing. No skills no graphical bug, but actually GONE! Now I tried doing missions going to different areas to see if it come back and different scenarios to see if was just minor bug.
I am 5-2 Knight about to be Rank 6. So its not like I should not have one.
I am almost sure you've managed to figure it out by yourself, but I think your Battle Sprite might just be unequiped. You can equip it by going to your Arsenal (inventory), click on Battle Sprites tab and then clicking on your Battle Sprite's icon.
You said you were playing with your friend who is "newer to the game". I think that means he has low rank and you were doing his early missions together. If you were doing one of the three Battle Sprites missions, your Battle Sprite was unequiped and you got some level 15 Battle Sprite instead. So when you finished the mission, you were without your Battle Sprite, because he hasn't been equiped again. So you have to go to your Arsenal and equip it again after these missions. I think this is what caused all of this.