When I first started raids, I absolutely could not deal with Spirit Link. Even if I had a debuffer on board, he never seemed powered up enough to dispel it. These days, Caedmon (or Sonya) can usually take care of that (and Perfect Riposte). Once I got Gunnar, I realized that he could help me get through some of the level 20 bosses without using a bunch of items, especially that creepy octopus with all the extra eyes on 20.2.
So anyway…why aren’t there any higher powered Heroes with Spirit Link? It’s easy enough to deal with in raids for higher powered teams, but it helps a bunch when you need to farm high world levels. For all the other powers, they at least have a 4* counterpart.