Is Oddone really a sub for TSM?

He is and isn't at the same time. A bunch of teams (specifically NA ones) have a habit of honoring some of their best players by making them permanent subs on their teams (in an effort to say to them that although they probably aren't going to be playing with them anymore, they're still "with us" on the team). TLA did it with dom, CLG did it with one of their old mid-laners back in 2015 before they did the whole "rebuilding" thing, and TSM's more or less had regi/oddone as subs ever since they stopped actively playing. Since you can't retire jerseys/hang them from the rafters in e-sports, perma-subbing them is the next best thing apparently.

I think so. In the possible event that something happens to Svenskeren(like when Insec broke his leg) a while back. Or when Regi had to sub for a few games while Bjergsen had something to take care of.