VG Item: Atlas Pauldron

The ideal situation would be to hit it before you arrive. However, that would take some practice on your part. I'm not currently educated on the length of time it takes alpha to close the gap using Prime Directive, that length of time would also change depending on the distance to be closed. An overdriven Prime Directive seems as if it would take too long at full range, thus wasting the pauldron's effect. But if you learn the time it could be a very effective measure.

However, a lot of that depends on the level in which you play. I don't think many realize you can reflex an Atlas Pauldron Also, you have to remember that saw could still escape using Roadie Run, although this would have the same effect as an atlas by cancelling out his attack speed if he was fully spun up. Finally, I think most Saw players, especially Spun up, would stand there and attempt to battle it out with you and probably wouldn't realize you were hitting them with atlas until it was too late.

So the "perfect world" strategy would be to trigger it immediately prior to arrival so it triggers upon arrival, but that's going to take a lot of practice in timing from you. I personally would trigger it once I had arrived at the target. I think that would be have the more favorable outcome for several reasons. If you mistime it when approaching, you are probably going to be mincemeat for a spun up saw with an alpha. If they trigger their reflex block once you have arrived to block the atlas, you are still probably mincemeat, but you have two other teammates, and you just caused them to waste their reflex block, leaving them susceptible to more harsh attacks like the various ults or burst damage that may land as a result of them not having the reflex block.