Makoa can shut you down VERY easily with a simple hook. Let your team bait his hook, or wait it out, then focus him down from above. He has a tiny chance of hitting you in midair with his slow projectiles.
Despite the obvious counterplay, don't use your ult exclusively to counter Makoa ult. He can simply wait for you to die to use his ult, and you can charge yours significantly faster than Makoa can charge his anyway.