You are not ready for Tren. Clean up your diet, test dose at 400 couple times a week is too high. Stick to trt dose of 200-250mg week, this will keep the bloat down and no need for AI. I didn't touch Tren until I got to 11% bf which in hindsight wish I would have waited till single digits before hitting it up. Start doing cardio after every weight training session 4-5 times a week and see the fat melt off. Good luck.
if its underground gear he might need to inject "1000"+mg's just to get replaceement levels. lots of underdosed shit on the market.