Wraithlords are towering wraithbone constructs imbued with the spirits of dead Eldar warriors. They're bigger than the human-sized Wraithguard, and instead of carrying guns that rip holes in space-time, they're either carrying heavy weapons on their shoulders (like a big-ass rifle) or huge fucking swords.
The one pictured has has all the heavy weapons it could fit on its shoulders AND the huge fucking sword, but there are a couple of things to note in this regard:
- Purely in fluff terms, finding a dead Exarch in the Infinity Circuit takes a Warlock or specialist Farseer, so the very notion of talking the Exarch into a wraithbone shell with no dick is setting a pretty high bar in the first place.
- But suppose you achieve this. The Exarch's in the Wraithlord, and now the whole thing comes to life, and starts grunting "Diiiiick! Where's my diiiick?" and heads straight over to the nearest shelf of space-hairdresser weapons, and sticking too many giant anti-tank weapons on its shoulders, AND a huge fucking sword. You, the bastard psyker who incarcerated the poor fella in there is hardly likely to start arguing with it about 40k game load-out limits, now are you?
- I think not, no. You'd be checking your runes, and pointing the thing in the direction of the nearest Dreadnought with a certain malicious glee in your psychic heart, wouldn't you.
And I can tell you for nothing, that in game terms, it's worth the time spent dicking around with magnets just to see the look on your opponent's face!
On the Tabletop
In 8th Edition Wraithlords clock in at 103 points, an odd but reasonable number for what you get. T8 W10 and a 3+ save will keep it in the battle for a while, but sustained fire WILL take it down due to its lack of Invulnerable save. Additionally, when at 50% and 20% Wounds remaining it becomes a lot less effective, dropping its Movement, WS and BS by 1 for each step. And while an 8" move, Strength 7 and WS 3+ looks good on paper, having only 4 attacks means that it's not likely to kill a lot of infantry. The Ghostglaive is not very expensive at 10 points and gives it a whopping Strength 9 AP-4, it's more suited against tanks or a wounded Monstrous Creature than blobs of infantry. And given how easy it is to Fall Back now, it cannot easily tarpit big units of infantry. Even then, a Wraithlord is not very likely to kill a 10-wound tank in one turn unless it's fully kitted out. The Wraithlord is best suited for ranged combat, where it has five options for its heavy guns. They can pick two of them in any possible configuration. It is possible to pick two of the same and get some extra firepower, but with the new rules a model can pick different targets for different guns so there's no real punishment in doing so. And do not forget that you don't have to shoot all guns of the same type in the same go: if you can destroy a target with one Bright Lance you can aim your other one elsewhere.
- Shuriken Cannon are one of the cheapest options at 10 points a pair. The only Assault weapon in the list, they are also the shortest ranged of the bunch. No armor penetration unless you roll a 6+, but it makes up for it with a reasonable S6. Don't expect them to perform miracles, but they might work against small blocks of infantry getting too close for comfort.
- Scatter Lasers cost the same and have the same S6 as the Shuriken Catapults, but are Heavy 4 and have 36" range to harass infantry at a longer range. No chance at the -3 AP that the Shuriken Catapult has, but this is not your weapon of choice against high-armor save units anyway. Can be used against larger units of infantry at a longer range.
- Starcannons are the Eldar Plasma weapons. Clocking in at 30 points per pair, a Starcannon delivers a man-melting S6 AP-3 DD3 damage blast. Now that many heavy infantry models have multiple wounds, this means that the Starcannon can do what Imperial plasma weapons struggle with. Even then, 4 shots at BS 3+ is not going to clear out entire units in one go and they struggle against 3-wound units.
- Bright Lances are your premier anti-vehicle and anti-monster weapon. 36", S8, AP-4 and D6 damage means that it can really ruin the day of whatever it hits. They are expensive, but you can't beat them for vehicle popping power. And if you get lucky you might get to use them on a character and vaporize them, but don't count on it.
- Missile Launchers come in two fire modes: D6 S4 AP-1 shots to deal with infantry (note that it fares better than the Imperial counterpart) or a single S8 AP-2 D6 damage missile to put a hole in all but the toughest tanks. Less powerful than the Bright Lance against big targets, it makes up for it with its longer range by being a decent weapon against light infantry. Taking two will increase your Wraithlord's cost by 50%, so do be careful.
Then there are the wrist-mounted guns. Shuriken Catapults deliver 4 shots at 12", which won't do a lot of good for you. The Flamers however are a whole other story. Getting two means 2d6 auto-hitting attacks, which is great even at S4 AP0 D1. And if you get close enough to an enemy vehicle and unleash these you might be surprised: as long as the tanks has Toughness 7 or less you're wounding at 5+ and it gets its full save. While these are pretty bad odds, shaving off just one or even two wounds might mean the world when the Wraithlord charges in for the kill.
Because they have the Spirit Host keyword, they have synergy with Spiritseers. If you get one within 6" of an enemy, the Wraithlord can reroll all of its 1s on the To Hit rolls against that unit, which can prove to be a life saver when dealing with high priority targets. Do note that this does not work for Flamers.
But are they worth it? Not really. They can get really expensive really quick, and the Wraithlord has a superior counterpart in the Eldar War Walker. While more fragile they're a lot faster, don't deteriorate under fire, get a 5++ save, are cheaper each and can be taken in a squad of 1-3. This means that with twin Starcannons they're only 121 points each instead of 163: still expensive but not that much more. Do note that they clock in at 85 points each at minimum, but upgrading weapons is 12 points cheaper. So just take them instead.
When dealing with Power Ratings all of that goes out the window. Sure, Wraithlords are 2 Power more expensive than a single War Walker, but they get a tougher frame, two extra small arms and a potent weapon for those measily 2 points. They might not be as fast and lack the save, but they make up for it with all the other perks.