and now question I'm confused for some days - Are "Path to the grave" beating enemies immunity? So can I then made double dmg by fire to fire immune, etc. for this one use?Grave Domain.
Offered as a nicer alternative to the death domain the Grave domain packs in quite a few interesting abilities.
First up you get a lot of spelks that don't transform the class in any significant way as they are already spells the cleric for the most part gets already. And they're not exactly spells you would pick anyway. Overall for the most part a fairly lackluster effort.
Circle of Mortality
This looks like a great ability and first. In practice more often than not its a maximised healing word. Spare the dying at will bonus action 30' range is useful but one can argue a cleric that doesn't let allies drop in the first place is an even better idea. Still all of these abilities are useful and are not bad as such.
Eyes if the Grave.
AKA how to annoy your DM. Marginal use in most games although useful in undead heavy games. Very situational and limited though and campaign dependent.
Channel Divinity. Path to the Grave.
This ability looks great. Mitigated a bit by you giving up an action to double the next amount of damage dealt. Useful but it kind of depends on that source of damage. Compare with a death or light clerics inflict more damage full stop now. Still more damage generally always useful.
Sentinel at Deaths Door
You will be popular in any party you are in. You can negate most incoming critical hits. Not to shabby.
Wisdom modifier to cantrip damage. I prefer this ability over bonus damage to weapon attacks. Wish the death cleric got this.
Overall the grave cleric should probably be played as a support character. Nothing wrong with that. However I think there's just better option in that niche such as life domain. Overall I would make it a B tier or B+ being generous. It's not going to be as good as dedicated support characters (read as Bard or some clerics and druids).
Even comparing it to other clerics there's just other ones I think are better mechanically and from a powergamer PoV. On the plus side it's still a good domain nothing wrong with it.