If I'm Big Z...
Russia would give up the lands it holds in Kharkiv, Suny, and Dnipropetrovsk. They ask for the remaining Donbas, the rest of Donetsk and Luhansk.
The first bit is laughable, Russia only occupies small swaths in these 3 areas near Kharkiv. But at least it shows Russia is willing to Concede something. To get the rest of Donbas in exchange is wildly unfair (but, ya know, life and especially war isn't fair)
In Skyrim terms this is Stormcloaks giving up Riften to gain Morthal.
They would freeze along status quo lines in Kherson and Zaporizhzhia.
Fair enough, these lines haven't moved in years and the river seems to make it too risky for either side to even try anymore. But still, this isn't a concession, the deal hasn't been swayed my direction by this because I don't believe Russia can cross the river even if it wanted to without massive casualties it isn't prepared to sustain.
He also sets a hard line of no NATO expansion in Ukraine, a requirement of Ukraine excluded from NATO, having its military wound down
See now this is the tough one. If Russia does not plan on launching another land grab invasion, what difference does it make if the now greatly diminished Ukraine joins NATO? Wind down the military, sure, that's kind of implied by ending the war and thus ending mobilization.
and will only agree to 3rd party peacekeepers from China, not NATO countries.
This last part must be trolling. China may or may not support Russia in this mediation, but it sure as shit does not support the West and represents a glaringly obvious bias. I'd feel better if it was America under Trump - though a NATO country, is the one that doesn't need permission to wag its power around and its current leader benefits enormously from a clean mediation and peace agreement.