Guys, you're overreacting. The main issue is not Jhin's Hail or Blades nor is it the new item that synergizes too well with him. It's usually your decision to run from him in the first place. Hail of Blades has less overall damage output than Conqueror and less than Summon Aery.
The reason this new meta Jhin beats you is because 1) you run from him unnecessarily and that allows his Hail of Blades to refresh(assuming you successfully disengaged/escaped) and do more damage again or 2) his support is doing too much damage and enhancing his executioner's damage or 3) you forgot resolve and don't have enough health to avoid dying to his executioner's damage. If you're not taking Second Wind every time against a Jhin, I don't want to see you crying about your health pool disappearing because you can't handle his executioner's damage. It will be a buffer against his lane partner's harass so that you can duel him without getting too low.
Regarding his passive, the wiki tells us:
The fourth attack is guaranteed to critically strike, dealing 15 / 20 / 25% [at levels 1 / 6 / 11] of the target's missing health bonus physical damage.
And as for the ultimate:
Curtain Call's damage is increased by 0% - 250% (based on target's missing health), and the final shot critically strikes for 100% increased total damage.
Either zone out his lane partner or find a way to heal back the damage they are causing, or expect Jhin to do what he does best. You shouldn't blame your opponents for your own mistakes.
Lane partners for Jhin like Brand are totally beatable, but a lot of people don't know how to play against whatever lane partner Jhin has. That's not the lane partner's fault, that's their enemies' fault, that means you and your lane partner for not knowing how to best avoid their combos.
I have to admit though, that Jhin's W is a lot scarier with someone like Brand in particular helping him since his damage over time can get very dangerous.