From what I've read, it seems that Kyreum W is harder to counter/check than Kyreum B I've been searching for checks to this beast and the best i've found so far is special defensive heatran. I've provided some calcs to prove this. Naive 252sp.att +lifeorb Draco meteor vs 252sp.def and 252hp, calm heatran= 32.38%-38.08% Modest 252sp.att +lifeorb Draco meteor vs 252sp.def and 252hp , calm heatran= 35.75%-41.97% Naive 4att +lifeorb Outrage vs 252sp.def and 252hp, calm heatran= 21.76%-25.65% Modest 252sp.att choice specs Draco meteor vs 252 sp.def and 252hp, calm heatran= 41.19%-48.45% Timid 252sp.att choice specs Draco meteor vs 252 sp.def and 252hp, calm heatran= 37.31%-44.3% As you can see heatran can tank the strongest move in Kyreum Ws movepool and can't even be koed after draco meteor+outrage. Of course heatran can't take earth power without air balloon and focus miss without chople berry. Most Kyreum Ws wont be running focus miss due to fusion flare taking out most steels so air balloon would probably be the most suitable item in this case. What is apparent is that heatran can definetly take on the specs set with good prediction. It can even fight back with dragon pulse or torment to screw up kyreum. 4sp.att, calm dragon pulse vs 0sp.def and 4hp Kyreum= 45.92%-54.59%. What is even more astounding is that heatran can actually survive a draco meteor+earth power from the life orb set. 252 (-2)sp.att, naive +life orb earth power vs 252sp.def and 252hp heatran= 62.18%-73.58%. Its a shaky risk to take but, providing minimum damage and at full health, a naive draco meteor+earth power cant ko heatran. I think this calculation alone should make heatran one of the few reliable checks to Kyreum W.