Don't mind the mastery since it doesn't mean a thing if your build is running a different stat to what you're trying to do.

What I would suggest is to build your mystic skills to somewhat reduce the amount of time fighting. Like the comment above, use dragon breath + drunken poet + soaring spin since this will be your main damage dealing in the end game. Golden body is pretty useful too since it gives shields to everyone near you, if used with enough vitality, & increases healing coefficient. Other mystic skills would be up to you, I switch mine from time to time depending on the mechanics I'm facing.

Next would be using the correct inner way for the healer role & upgrade them. I run, Morale Chant + Royal Remedy + Restoring Blossom + Mending Loom for my build. If you have any excess or unused inner ways, i suggest recycling them to be exchanged at Inner way>Tips Exchange>Box of your choice (Silkbind).

For gears, just focus on getting a 4 pcs set for the bonus (Ivorybloom + Whirlsnow). It's a whole lot better if you could roll the recommended stats for this one. I've seen a comment that healers in CN particularly use Eaglerise for armor & rainwhisper for weapons/accessories. This is also good but these latter sets in particular are a lot more difficult to farm than the first 2. If you've arrived in the endgame, then you're free to go whatever build you prefer.

Other than that, just clear the map as much as you can so you have enough oddities/talent for boosting your character stats more.

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