Will it help if Astro have slow Effect add to Gravity?

[Dnc]

But Arm's leng is 120s recast time and maybe it's better for tank to save it for knockback.. I guess..

True, but at least when it comes to big pulls Arm's Length can be very useful for "mitigation" purposes. And I have a feeling the dev team doesn't want to diminish it's usefulness in those situations.