For what’s worth, my MC made it through that mission with these stats:
used the suppression crown, 1x agility and 1x strength talismans and activated energy infusion (with a trait) for +20, to clear all the checks (except one constitution fail, took 50 extra damage) Used 1x healing talisman after the first round, and 2x regeneration to get back to near-full after the second.
It was very much down to the wire (like with ~20 hp left after 2nd and 3rd rounds) but it’s otherwise doable without inflated stats. There’s also option of bringing more healing talismans if you lack regeneration, putting more exp in Vitality to increase your health pool, or just skipping the fight altogether (let the escort die, and if you’ve seen through Mei Mei’s ruse then you’ll also figure out what’s going on here, so you can complete the mission this way)
If you insist on a fight, it does say it’s very hard mission in the difficulty warning and it ain’t kidding, but i’d say that’s fine.