was buffed yes. Before 5.4, if the Haunted creature died before Haunt expired, then the Valkyr would never ressurect. Its much less risky to use now, and could arguably use a nerf for being too good an ability for delivering safe damage.
But using an aquatic pet will pretty much amputate a Valkyr. Beside taking 33% less damage from undead abilities, dots are reduced by 50% on aquatic pets.
Plus I sometimes see Haunt being played badly, like someone playing it while they have one dead pet, and reducing their numbers to 1 active but wounded pet. If you can manage to kill it before Haunt ticks down, then youve won because all their pets are 'dead'.
Or in other cases, people throwing away their victory by Haunting my wounded last pet, while they had no other pets left. Big Oops there!