Hello,
Oh the poor dragon.
I simply don't understand how people can abuse animals like that.
The wound looks like it could be infected so as suggested, use antibiotic ointment or unpasteurized honey to help out.
The pores being clogged can cause some discomfort, too. I am sure he is feeling some pain so that would explain some of his aggression along with not being handled at all.
I would recommend a vet visit just to see exactly what type of infection is going on.
The sperm plug will eventually work itself out so a daily
bath can help with that also.
Let us know how he is doing.
Tracie