having not bought this doctrine yet - can someone tell me how it works? do i have to click a button each time I want to normal attack a unit? does it only last for a little while?
I was confused by this too. The video in the Codex was helpful.
My understanding is that once you activate the ability, all attacks are much more effective against infantry, for about 20 seconds or so.
^ LOSTINSPICE is correct, it's a buff that changes the damage type to normal.
Wraithguard attacks also seem to have some splash so if you can catch a blob with rifts you can wipe them. Best thing to do to counter is to spread your units or back off and wait the timer out for it to go on cooldown; there's about 30-40 seconds downtime.
This ability is AMAZING. I bought it and love it. Yes, the damage is splash and it wrecks people. It turns the wraithguard from anti-armor to the backbone of my army. A single triple shot of your unit will kill a space marine infantry squad. I plan to couple it with the other doctrine that increases the wraithguard's attack speed and siphons their shields. I might end up putting to many eggs in one basket, but I at least want to try it because wraithguard doing normal damage is insane and if they could only attack faster to get more shots out, oh that'd be glorious.
One thing that I've done is not use this ability on all my wraithguard at once. I'll use it on roughly half of them and they'll unload in infantry and decimate them in the 15 seconds it lasts for. Then, while the others might not be dealing much damage I'm looking out for armor and using them to pop tanks if I see any. Then later in the fight I'll them prepared for anti-infantry as well. I get some dark reapers and wraithblades with them, too, but mostly just from already having them from earlier in the game.
I love all the wraithbuddies and will use the wraithlord as well so I can just run into a base with the wraithlord and then summon my entire army of wraithbuddies. Wraith dudes are so slow, but the wraithlord and webways fix that.