> Position ourselves so we are a bit off-center above the behemoth's spine, enough that the fins won't slice into us as its moves along its current path.
> Get a two-handed downward-stabbing grip on our sword, with the sharp edge of the blade facing out along the behemoth's body toward the tail, and give the behemoth's back a good stab. If our blade actually sinks in, use our hold on it to try to keep it sunk in.