When you do the first mission with the emporer dont leave the emporer yet so now u need to attack barrus and keep fighting him this will not add anything to ur bounty but for heavy armour skill you may need a few repair hammers also u can work on ur block skill and blade skill alo u must drop a dagger when barruses weapon breaks when desired u can still leave the imperial sewers but u cant go back to train of him when u help martin also he dissapears when u do the dark brotherhood mission where u have to kill theat annoying prisoner from the begining happy gaming and good luck and aslo give me thumbs up lol