Denying follow-ups with Helbindi?

You could use Chill Spd as well to deny the fastest unit on the opposing team from doubling if they have less than 43 speed.

I think it's an interesting idea, but I'm not too sure on how efficient it is. You may just want to tank the second hit with your higher defense instead to accelerate your special (And your opponents unless you run guard).

as much as I like stacking speed on seemingly slow units, 21 base speed just can't be salvaged without sacrificing a lot of what helbindi can do. you be better off just using things like close or distant defense + quick riposte and something like atk ploy. I kinda think any speed stat below 27 is not worth salvaging

What if you invested the same amount into his def or his res? Would you like the results better?