All is in the title… Can a hero who’s the guard of a tower come on a fight on the tower and fight twice ?
If he can fight 10 times instead of the usual 5?
No, that should not be possible.
I never saw it happenning, but if it does, than it’s a bug
Answer is no. You effectively fly to the tower and fight there and then fly back to where you were. When you fight through your tower, it uses your energy so moving to your tower to fight is actually a bad move. (It may even use your troop total for calculating SV though I’m not sure about that.)