[As both a DM who has had a player use a Beast Master, and as a player who has played a Beast Master, it always bugged me that the beast master’s companion was incredibly lacking when it came to health and heavily hindered their master’s ability to do just about anything.]
[What I did like was how the Unearthed Arcana Revised Ranger went about scaling the companion’s health, and its ability to act on its own without consuming its master’s action, but I much rather preferred the PHB’s other subclass features, so I combined the two and edited the PHB traits to accommodate for the beast’s newfound freedom.]
[On another note, I decided to throw some subclass spells on the PHB subclasses to put them on par with the XGtE subclasses.]