It did always feel that the beastmaster should suffer some kind of psychic shock, limited number of pets than the Druid. The Warlock already has limitations on his special creature as it slowly kills him if he keeps creating more. But it seemed that the beastmaster could care less that his 'pet' just took one for the team.
I guess thinking mythology wise Dryad's were linked to a tree - and died if the tree died, so I can see some parallels to the Druid there. But it seems odd to limit it to a single tree with no other health/consequences. It could have been like a reverse of the Warlock, a health bonus when the treebond is made, but an actual penalty if the bonded conjuration dies; due to psychic shock.
Anyway, just musing. It does all look great!
This is actually a bit of both. It's quite a strong "special marker", but it's also because of the Druid's themes. She's a guardian of nature, her trees are part of her.
