|Necron version of TH/SS Terminator|
Let's look at the built in advantages of Lychguard:
1. S5/T5--They hit decently hard and their toughness helps mitigate low strength attacks.
2. Power Weapon attacks--With either wargear choice, they are packing PWs
3. Can take Warscythes to open cans and smush just about anything including LRs
4. Have a 4++ Invulnerable versus both CC and shooting (and can actually bounce shots onto enemy units)
5. Can take Reanimation Protocol rolls (one major advantage over Wraiths)
However, there are several weaknesses that I think hold them back:
1. Cost--At 40+ points per model, they are expensive for a model with a 3+ save.
2. Mobility--They are slow and do not have access to assault transports
3. Lack of Fearless or Stubborn--This is a huge one... Praetorians get it but Lychguard don't? Boo...
4. Low Initiative--Means they have a hard time getting to strike back and are vulnerable to getting swept
5. No Invulnerable with the Warscythe
6. No 2+ save... Missile spam is going to wreck their world
7. No Grenades--Normally won't matter unless they are going toe-to-toe with Termies or other I1 models
The big advantage that Lychguard have over Wraiths is Reanimation Protocols, and I think that is something that has to be capitalized on. They need to be given a Res Orb to help improve their ability to get back up. The 4+ RP roll helps make them comparable to two wound Wraiths. A Warscythe Lord with Res Orb is great because it provides the Orb, along with another Warscythe that can't be singled out in CC (useful in a Sword/Board unit). Nemesor is another option for a Res Orb, and he brings along some other benefits (discussed further down).
The biggest weakness that Lychguard have is lack of mobility. They are infantry and cannot get a real assault vehicle. The only way to increase their speed is through a Veil, a Nightscythe, or a Monolith. Unless they change how Monoliths work in 6th Edition, pulling Lychguard through the portal doesn't help as they cannot assault afterwards. And if the Monolith is close enough to dump them out anyway, it is probably melta bait already. The Nightscythe is even more problematic as if it gets shot down, the contents go back into reserve. At least with a Stormraven, you can go flat out and hope to survive--even if you don't you are still standing in the wreckage. The only thing I can see working with a Nightscythe is to deepstrike it (possibly using Nemesor's ability) and then hop the Lychguard out of it. A Veil is workable, but removes the ability to have a Res Orb Lord in the unit. There are a couple of workarounds for this such as attaching a Res Orb Overlord or using Obyron to provide the Veil.
The next step is trying to figure out what role the Lychguard are going to play, as that is going to drive how they are equipped, how they get a Res Orb, and how they get mobility. If I want to use them to handle big nasties like TH/SS Termies and MCs, I need the Sword/Board variety. Likewise, they need an attached Lord with Warsycthe to provide extra punch and keep them from getting locked down by Walkers. Throwing an Orb onto the Lord would allow them to slog up the field in front of the main lines and provide some infantry-based cover. Adding Obyron to the unit would provide them with mobility and more punch, but I think it bumps the cost up too much. With the Lord, they are already clocking in at 300 points. Another 160 points just makes the unit too costly, considering their only role is to catch Walkers, MCs, or PW-toting squads and grind them down. The problem is that Scarabs or Wraiths do that job better and cheaper.
Warscythe Lychguard sacrifice the survivability of the shield for more offensive punch. They will shred any vehicle they touch, including LRs and Monoliths. MCs and Walkers better hope they smash all of the Lychguard before the robots get to strike back. However, missile spam or battle cannons are going to shred the unit. Basically, this unit is a bully unit that is going to go after things that can't hurt it, rather than try and grind down units that can hurt it. An Overlord is better for providing an Res Orb, as there is no need to attach a Warscythe Lord to the unit. This also allows a Cryptek to be attached to the unit and provide wargear such as defensive grenades or a Veil. It's still a 200 point unit plus the cost of the Cryptek, though.
I think the missing piece to this puzzle is Nemesor. He provides not only a Res Orb, but also a 2+/3++ body to catch incoming fire. Not only that, but he can provide vital rules to the Lychguard including Furious Charge (S8 on the charge... yes please), Counter-attack, or Stealth. I think he goes well really well with Warscythe Lychguard as he completely negates the need for an attached Lord. Also,he can help soak fire that would normally kill them and provide Stealth to give better ranged protection than shields. They will still get wrecked by large squads of PW-toting models, but those can be handled with close range fire. He still works well with Sword/Board Lychguard, but they really do need the attached Lord with Warscythe, limiting the effect of his savings... and preventing a Cryptek Veil from being attached to the unit. So they would have to either have to footslog (which they could do) or have Obyron attached. And unless the FAQ allows Obyron and Nemesor to deepstrike together without scatter, that is still just too expensive.
So I am going to build off my other Nemesor list and see if I can swap Wraiths for Warscythe Lychguard. Dropping the Wraiths, a Res Orb Lord, and two Warriors provides enough points to pick up 5 Warscythe Lychguard, a Veil Cryptek, and a Gaze of Flame for one of the Lance Crypteks:
Overlord with Warscythe and CCB
3 Lance Crypteks (1 Solar Pulse, 1 Gaze of Flame) and 1 Veil Cryptek
3 Lance Crypteks
5 Lychguard with Warscythes
10 Tesla Immortals
5 Tesla Immortals
5 Tesla Immortals
9 Warriors with Ghost Ark
9 Warriors with Ghost Ark
This setup provides me with multiple options. I can attach the Veil Cryptek to the Lychguard or to an Immortal squad to provide them mobility. Between the Veiling Lychguard, the CCB with Warsycthe, and Scarabs, I can actually take the fight to an adversary. If the Lychguard don't need mobility, I can provide them with a Gaze of Flame to make them harder to kill in CC (Counter Assault and Defensive grenades... nasty). I can also split all the Crypteks up into different squads and keep the Warriors mounted (if I was to run all the Immortal Squads as 5-man squads), or I can run two Squads of Lance Crypteks in the Arks. I still think my previous list is stronger, but this one should still be able to hold its own at the RTT-level.
If I was going to change this for a Sword/Board unit, I would simply drop the Veil Cryptek for another Lance and just march the Lychguard across the board. They would be slow, but could act as a solid speedbump to protect the rest of my army from big nasties.