Vorpal Blades Question

I feel kinda stupid asking this, I worked with the Editor for a long time and know a lot of advanced things about it, and here I am stuck with something that seems so easy. Anyway, I'm trying to get the unit's attack to pierce through initial target and damage those behind (for full damage). Sounds exactly like the description of Vorpal Blades, right? Well, I gave the unit Vorpal Blades ability, removed the research requirement from vorpal blades, and... nothing! Is there some other requirement I need to fulfill for vorpal blades to work? I originally had "instant" for unit's attack, tried changing it to "artilery (line)" and "missle (line)" both of which didn't help, if it matters the unit's attack type is "Pierce" with no splash, I want to keep it's type as pierce, need it for balance issues. Thanks.

EDIT: After further examination I see that Vorpal Blades Ability does nothing other than taking up space in unit's menu. The real effect comes from the the upgrade enabling unit's 2nd attack and increasing splash. I need a solution that will let me pierce through the actual target and damage those behind as opposed to damage targets in front of the targeted unit. This is because units automatically target closest target, so there won't be any use to this since there is nothing in front of the closest target. What can I do about this?

Well, by looking at the Glaive Thrower, I can see that the only actually difference between attacks 1 and 2 is that attack 2 can target Trees.

Therefore, I think that the Vorpal Blades ability might, in fact, do something, but I think it might only work if the unit has a "Spill Radius" enabled. I don't believe that "Spill Radius" is related to AoE damage, especially because most units that have AoE damage do not have a Spill Radius value. Try giving your unit a spill radius and researched or requirement-less Vorpal Blades and see if that works.

There is another thing you didn't notice about 2nd attack that actually makes it sem like it pierces through first target, its attack is set to Artilery (line) causing it to mow down anything between its target and itself.

I think that they both had Artillery (line), but I'll check again in a bit.

You're right, guess I looked somewhere else when I checked then. Perhaps the game only says that it pierces through initial target, when in fact all they did was added more splash.

I'm not convinced. I think it's possible that the combination of the Missile (line) attack and Spill Radius may do what they say it does, or else there's something else completely different going on which we don't have the ability to discover.

Well, I tried using that glaive thrower on a group of units just to see how it works. It's not 1 directional splash, the splash from it goes in all directions. And after the research its splash increases, but it doesnt seem to "pierce" targets like the description implies (note that I tested this with unmodified glaive thrower and unmodified vorpal blades research, meaning it does exactly what blizzard made it do). I think I got a solution to my problem though. I could make the actual attack obsolete do 1 dmg, and give a spell to the unit based on Shockwave, after unit attacks, a trigger sets off shockwave, and voila, it pierces!

I think it will be setting off the Shockwave from the location of the attacking unit, not the target, but yea, that should work.