Is Kindred Celestial in nature?

As so far as can be seen, it's extremely unlikely. Celestials appear to be some higher order of life - advanced, abstract, driven by goals almost unknown to normal human minds. Whether or not they're some universal force or otherwise is entirely up in the air.

Kindred is the personification of Death - they're a force of nature more than anything else. It would be closer to imagine them sort of as an elemental, perhaps, an embodiment of a concept. The embodiment may be destroyed or denied, but it will always return because it's apart of reality.

Like, aren't they more like a metaphysical law or something? Like bard isn't omnipresent and Raka apparently was able to lose celestial status. Do you think Kindred could stop being Kindred if they felt like it? I think that would be weird if they could. Likewise bars enforces balance or needs or something, he doesn't seem to be a law of the universe. Kindred prolly gets their own box. But I agree they have a similar feel to bard, personally Raka seems to person like to count