The Wraithlord is such a powerful and feared opponent that most enemies will try to kill them as quickly as possible. For this reason, it is wise to take at least two Wraithlords if you are going to field them. Wraithlords are so tough that they can soak up an incredible amount of heavy fire but they aren't indestructible and you can expect to loose at least one in the first turn if they aren't in cover.

The Achilles heel of the Wraithlord is their vulnerability to sniper rifle fire. A squad of snipers can easily kill a Wraithlord in one turn of shooting. If you are playing against an army that can field snipers (such as Imperial Guard or Space Marines), Wraithlords should start the game out of line of sight from the type of places that snipers tend to occupy, such as, taller buildings, hills and other places that that provide a wide field of fire.

To keep Wraithlords around long enough to be useful it is necessary to take out the snipers as soon as possible or at least "pin them".

The Wraithlords will repay the cost that it takes to keep them "alive" by killing most troops that they come across. Wraithlords are awesome in hand to hand combat, easily defeating most foes.

When in hand to hand it is worthwhile keeping in mind that powerfists can deadly to the Wraithlord.

When assaulting a squad that contains a character with a powerfist or similar weapon, it is a good idea to charge in a way to get into base to base with the character . The reason being that you want to kill the character before the character has a chance to damage the Wraithlord. When you finally get into base to base with that character you can allocate all the Wraithlord's attacks on that threat, to kill it. It is a bit of a gamble but you would have to be very unlucky to loose a Wraithlord in one round of hand to hand with anything, especially as the users of powerfists (except dreadnoughts) have to hit last. Once you kill the character, you can wade through what's left of the rest of the squad.

The Wraithlord has up to three weapons but keep in mind that it can only fire two if it moved.

The heavy weapon that you decide to take is mainly used to kill the enemy as you advance to get into hand to hand. Keeping the Wraithlord at the back firing is a waste of the Wraithlord's hand to hand prowess.

As you advance with your Wraithlords it is a good idea to keep the Wraithlords close enough to other squads to assault any foe that try to attack your squads.

Wraithlords can easily kill assassins and therefore they make an excellent bodyguard for a farseer or Avatar. Two Wraithlords and an Avatar will worry any enemy! Never mind the other things that you have in your army.

A common mistake that people make, is that they concentrate on the big things and get defeated by the little things. Although Wraithlords draw a lot of fire and sometimes don't last all that long, it is worthwhile remembering that while the enemy was shooting at the Wraithlord, they weren't shooting at much of the rest of your army.

As your Wraithlord makes a very durable weapons platform as it moves forward at the head of your army to take out enemy vehicles with a Bright lance or Eldar Missile Launcher.

Wraithlords make a perfect diversion and can enable you to achieve your goals by drawing fire with them. If there are two Wraithlords and a couple of Wave Serpents, not to mention the rest of your army, on the table, your opponent will be in quite a state trying to assess which is the greater threat. Your foe will probably split their heavy weapons fire (a mistake) and therefore reduce their chances of destroying very much.

CHOICE OF WEAPONS:

The type of enemy will determine which weapons to arm the Wraithlord with, with.

Two flamers can be very effective as the Wraithlord closes in on massed troops with lighter armour.

Against all armies, a Star cannon would be a versatile choice. Star cannons are very good against heavily armoured troops like Marines and light vehicles. Star cannons are the antidote for terminators.

If you're playing against a heavily armoured foe such as Imperial guard, a Bright Lance would be a good choice. As tanks will be your target. The Bright Lance is a better choice in most cases than the missile launcher because for 5 points less you get a better chance to penetrate tanks and terminator armour.

As for the Eldar missile launcher, I think that even though it has greater range than the bright lance, the Bright lance has a better chance to penetrate thicker armour and it is cheaper in points. Against power and terminator armour the Star cannon is better than the missile launcher.  The Eldar missile launcher is good against armies that have lightly armoured massed troops like Imperial guard and Orks.  The plasma missile option is good against such troops as any squad that suffers a causality must test for pinning.  Some armies like Dark Eldar and Orks have many vehicles that don't need the penetration abilities of the bright lance and the extra 12" in range can come in very handy.

A shuriken cannon is a cheaper option that would be very good against armies with massed troops with low armour saves, such as Orks, Tyrranids and Imperial Guard.   Unfortunately it's difficult to get within range with out taking a few hits oneself.

Scatter lasers are too unreliable and not hard enough hitting to be put on a Wraithlord.