Mew is blue
Ah, yeah, I can definitely attest to Kingdra's usefulness. Specs is just super strong, and rain teams usually don't have an answer for it outside of ferrothorn (even ferrothorn takes ~40% from specs draco meteors, which is nothing to sneeze at). You're right that, even though it shines particularly against rain teams, it's not dead weight at all against non-rain teams. I think C-Tier is a comfortable spot for it. PS- Sleep talk on the specs set is soooooooo good.