Rivalries in the J are perhaps more of a fickle thing then the SHL, due to constant roster turnover and the fact that it's more difficult for teams to maintain a constantly high level of success. That being said, I think from an NL perspective, our biggest rivals would be CAR. The two teams have been on pretty much the same trajectory since the switch to FHM: a slightly down season gearing up for championship windows, followed by 3 seasons of high success, and back to rebuilding now. In fact, from S54-S56, both teams were #1 and #2 in the east each season, with NL 2 and 1 point above CAR in the first two seasons, and CAR 3 points ahead of NL in the latter. Ultimately though, rivalries are made in the playoffs, and this is no exception. Seasons 54 and 55 saw the teams meet up in the semi-finals, both series going to 7 games. In the end, the success was split 1-1, and each time the winner ultimately went on to win the cup.