You are correct! My bad. Oubliette was errata'd and it's a different case. Most Old School community play under these updated rules. So Triskelion would just phase back in with whatever amount of counters it had. There are still, however, hardcore players who use the old rules entirely.
Reprints of Oubliette say the creature phases out, which wouldn't trigger Triskelion's ETB. Do Old School rules ignore the errata?
You are correct! My bad.
Oubliette was errata'd and it's a different case. Most Old School community play under these updated rules. So Triskelion would just phase back in with whatever amount of counters it had.
There are still, however, hardcore players who use the old rules entirely.