The Immortality of Hoyt

Ulam will be important because we don't really get any specific proof that Ulam is trying to help Hoyt in any way. I question whether or not he still has his spren bond at this point. Maybe they figured out a way to make the bond to travel, but maybe not. And I think even aside from all of the powers that he is stacked, as you're saying, I think the immortality is separate from that. Possibly a remnant of holding the Dawn Shard or possibly a side effect of whatever happened at the shattering of Adonalzium.