Not a bug. It’s a choice by some players to leave the least powerful team possible to maximize defensive losses for retaliation.
The added the hero automatically joining the battle to avoid bugs with no opposing troops.
Ah, thanks. But I said it was normal, so I understood that part, but I thought that the hero would showen up before the battle.
Sometimes it will show the Hero for me (when that is the only character that they use), and others it will be a blank screen, like your screenshot. It seems to be sort of random if it shows or not.
Edited: After further thinking it may not ever show when they only use a hero, The character that it showed may have been the one regular troop that they used. I will have to pay closer attention in the future and get back to ya on that one.
Thanks for the reply!