Time to contribute to my favorite Brawler main
Ok Muto is pretty simple to say the least. If you're in the main game (Devil Beater) I personally think the best thing to actually do (in lategame like acts 30 onwards) just spam turret because every single other move is going to get you killed unless if you use your r to get some distance between you and the boss. Early in the game though, you can use MUTO's R and E to get some massive lifesteal (they lifesteal around 50 I think). In brawler, I suggest you use E to trap opponents (because it circles around a point) and use R as a primary attack. F is also helpful near the opponent. LMB is almost near useless, but it's nice for chipping away hp against slow opponents (if they don't kill you first).