proxy mtg cards Magic: The Gathering exile target instant or sorcery card with mana value less than or equal to Arcane Proxys power from your graveyard Proxy card - Wikipedia

Yes, yes, yes, and yes

Some mythics win games by attacking, others win by generating so much value over time that your opponents cant keep up

This works because state-based actions are not checked until the spell has resolved, and so there is no opportunity for the owner of the commander that was destroyed to then send that commander back to the Command Zone their first opportunity to do so is after the spell resolves

So I don't see a real reason to run Li Shang

Here are the hallmarks of the JRPG genre as I explained them in my vision design handoff presentation

You see, you need one hundred or more tower counters on Helix Pinnacle in your upkeep to win the game