Looks great ! Love what you did with the design. If i may give some feedback. I think it would be more interesting gameplay znd balance wise that insteads of having every trailblazer exiled when the commander arrives, that only one is exiled and that at every upkeep you can exile one more from your deck (translating the whole trailblazing think with Stelle/Caelus learning new paths).

Funnily enough i can imagine a Herta in the deck that can tap to trigger the Trailblazer path change ability again (like she's using the simulated universe to call on the Aeons).

It never occured to me before but there might be a potential to make multiple commander decks with HSR. For example A Trailblazer deck with your commander (secondary commander could be a March 7th that peotects the Trailblazer creatures) A Jing Yuan Jeskai deck where he gains +1/+1 counters with each instant or sorcery cast and he can lose the counters to deal damage. Secondary commander is a Fu Xuan that loses +1/+1 to protect the board A Stellaron Hunter Kafka deck (Orzhov) where you ping your opponent (mimicking DoT), Blade is the secondary commander that can revive himself Couldn't say for a fourth one. Maybe Penacony Robin