Editing Warhammer 40,000/8th Edition Tactics/Grey Knights (section)

===Special Weapons===
*'''Psycannon:''' 24" Heavy 4 S7 Ap-1 D1. The infamous weapon from 5th Edition. It has an arguably greater utility than it did in 7th, but compared to earlier editions, it's nowhere near the premiere auto-include it used to be at least in soups. This thing's best served against light/medium infantry outside of cover and weaker vehicles. Without buffs you'll only do .667 damage against T7/Sv3+ per psycannon, even when standing still, so psilencers are statistically better for cheaper against most targets, due to their increased damage.  If you want real anti-vehicle in the case of a soup list, just take more lascannons. However, with the new Tide of Convergence (ToC) ability, these bad boys goes up to S8 and D2, making their overall damage output very similar to plasma weapons who have better AP but a lower rate of fire, all the while being retarded explosion-proof. Then, stacking with Psychic Onslaught (2CP), will give your Purgation Squad 16 S9 AP-2 D2 shots! Point these psycannons at any vehicle and see it's armour crumble - against what is now the Grey Knights' strongest ranged anti-armour weapon.
** Given the fact that lots of things in Grey Knights are all about stratagem synergy, and you're likely going to be using your Psychic Onslaught strat on your psilencer Purgators, it is sometimes good to have a squad around with a base AP -1 to kill marines and termies.
*** As long as ToC is active, infantry psycannons do the best against units with: T6 Sv2+, T7 Sv2+/3+ and T8 Sv2+, compared to psybolt storm bolters and psilencers (without needing additional buffs).

*'''Psilencer:''' It's a 24" Heavy 6 S4 AP0 D1d3 gun that fires the condensed psychic power of its wielder. Literal mindbullets. Deals 1d3 damage, like a force weapon. As long as you don't move, your 3/2 more shots then a storm bolter for only double the cost, Not to mention having an easier time wounding tougher models, you're sure to force some failed saves eventually. Their precious plot armor can only protect them for so long.  
**On a Purgation Squad, Psychic Onslaught is CP better spent than on a team of rapid fire storm bolters.
**Note: Outside of Tide of Convergence, against anything with Toughness 5 or higher and a 3+ save -- e.g. most vehicles, Monstrous Creatures, etc. --  you're still only dealing an average of .88 damage per psilencer, but against those targets, so is the psycannon, and for more points.  Against the ''majority'' of targets, the Psilencer is your best option from this list - you need to be shooting a Land Raider for a Psycannon to do better, in terms of hard targets, and even then, it won't be better enough for its cost.
** With the new Tide of Convergence rule, psilencers become S5 and D1+D3... Now you comfortably wound almost all infantry and you wound T8 on 5s, plus your damage will be on par with Lascannons once your enemy eventually fails some saves. Not bad, not bad.

*'''Incinerator:''' Most expensive special weapon for 9 pts. 8" Assault 1d6 S6 AP-1, auto-hitting. It's now a +1 heavy flamer, but an 8" range makes it hard to use in a faction that relies on deep striking for movement without using Dynamic Insertion(1cp). Only really useful on Purgation squads with 4 of them, if only so you don't miss out on Advance & shoot.
**Your best chance of murdering a Culexus Assassin, and actually works decently against aircraft, but only if used en-masse. 

*'''Psyk-out Grenades:''' It's available on all infantry models, but I'll leave this here. It's only S2 AP 0 but does 1 mortal wound to Psykers and Daemons if you roll a 6 to-hit (no need for the to wound roll). Frag or Krak is better, with  Psyk-out situationally better if rolling a six has better chances to than anything else.