It's kind of complicated
If hurizen is smart he'd let onooki take out the third (since even tho the third is fast he can't really do nothing about flight)
And then hurizen with multiple clones shooting off different elementals may be too much for onooki to counter especially with lighting release here
But one can argue that onooki should be able to use fire and wind in addition to earth but hasn't shown
Onooki can win if third decides to take out hurizen
Third would win if hurizen decides to go after onooki first
Overall I think the third is the stronger of the three and has most chances of winning simply because hurizen is literal crap compared to the thirds defense