Ulric has 3 (4 with legendary m1) and Blossom has 2, so I don't see why 1 + ult would be considered "overpowered" for Sirius. That, and the fact that the healing from his ultimate is the only redeeming factor for how terrible that ult really is. Are you close to him when he ults -> run around it. Are you far away? -> Go out of range. Are you at mid range? -> Either just sidestep and dodge at least half of the damage ticks or just cc him with literally anything. He's stationary, not very difficult to force cancel.
Also his R is arguably the most underwhelming heal from a support in the game. You should use it very sparingly mid combat as literally all characters in the game will deal more damage to you with m1s alone during the time it takes for Sirius to cast it. If anything I think they should give him his healing on Counter proc back.
The only reason as to why Sirius would ever be considered decent in his current state, is because of his potential when it comes to chasing people and his ability to escape unwanted fights, but when all the newcomers learn to stop hitting counters that wont be much of an issue any more.