Circle of the Kami Guardian (Druid subclass)

[sandmote]

Final Ward
By 14th level your protection has allowed the kami within your ward to flourish into a great protector. The kami chooses one acre of forest to be your Final Ward. The forest will be somewhere on the material plane and you do not need to be anywhere near it when the kami chooses it.

While you are within your Final Ward you can cast Druid Grove at will.

Once per day as an action you can teleport yourself and up to ten willing creatures within 30 feet to your Final Ward. If you do you will all be returned to the place you teleported from at the start of your next turn.

You can do this at will by using a longer ritual instead. If you perform a ten minute ritual you are returned after one hour. If you spend one hour on the ritual you will return in 12 hours. If you perform the ritual for 24 hours you will be returned after a week.

I would personally connect the Kami with the Fey, and put this in the Feywilds. If having to go to the forest to protect it from some threat was meant to be a feature the location is fine.

Touch of the Yukki Onna Your skin gains a bluish tint. You are resistant to cold damage and when this blessing is chosen you gain the effects of an Armor of Agathys spell cast with a duration of 24 hours. The level of the spell is equal to the highest level spell the owner of the ward can cast.

9th level Armor of Agythys at no other cost seems a bit strong.

Blessing of Kami Sight Your eyes are a scintillating green. You gain the benefits of constant Detect Good and Evil and Detect Magic spells and you always know if an object or area you see is a Kami Ward.

Maybe break this into two blessings, each of which grants one of those spells at will and always allows you to see if an object or area is a Kami Ward?

Touch of the Shinigami Your complexion grows pale. You automatically succeed on death saving throws and when you kill a creature that is not undead or a construct you gain temporary hit points equal to the creature’s challenge rating.

Considering the number of DMs that stop attacking players once they're unconscious, maybe only grant advantage on death saving throws? Its a similar effect, but it's still possible for you to die that way.

You should probably also specify the minimum number of temporary hit points you get.