I would save the lash prince thing for a bigger game. As was said before, using it to keep the nightbringer away will make it a priority target, so I would only do it if you're playing with enough points to take two of them.
Although, if you really want to try lashing it away, you could always take a slaanesh sorcerer and stick him with plasma chosen of either tzeentch (for an inv save) or nurgle (for more toughness.) In general princes are better, but if you're taking them specifically for a psychic power, a sorcerer in a unit has minions to soak up wounds for him. Just make sure that if you do it this way, the sorcerer is in a unit with guys that can hurt the nightbringer with shooting, since they'll all have to go after the same target.
Of course, I have to agree with darklove that if you have lash, you're probably better off using it to bring his guys to you so you can smash them into tiny bits.
Oh, and another thing. While I wouldn't use them for this particular game, if you guys ever start doing bigger games and he starts taking monoliths and stuff to keep his guys away from you, I highly recommend fully decked out Noise Marines. They're a little pricey, but I always love the look on my necron buddy's face when he realizes I have troops that can both outshoot his and are much better than his in cc. The AP 3 on the heavy version of the Blastmaster alone is lovely, let alone the 9 other heavy 3 shots at a distance where he can only shoot each gun once. A Noise Marine's Blastmaster is also a nice way to pick off Destroyers, particularly since if they run out of range the unit has enough Assault shots at long ranges to still be shooting things most of the time while they're catching up.
Although, if you really want to try lashing it away, you could always take a slaanesh sorcerer and stick him with plasma chosen of either tzeentch (for an inv save) or nurgle (for more toughness.) In general princes are better, but if you're taking them specifically for a psychic power, a sorcerer in a unit has minions to soak up wounds for him. Just make sure that if you do it this way, the sorcerer is in a unit with guys that can hurt the nightbringer with shooting, since they'll all have to go after the same target.
Of course, I have to agree with darklove that if you have lash, you're probably better off using it to bring his guys to you so you can smash them into tiny bits.
Oh, and another thing. While I wouldn't use them for this particular game, if you guys ever start doing bigger games and he starts taking monoliths and stuff to keep his guys away from you, I highly recommend fully decked out Noise Marines. They're a little pricey, but I always love the look on my necron buddy's face when he realizes I have troops that can both outshoot his and are much better than his in cc. The AP 3 on the heavy version of the Blastmaster alone is lovely, let alone the 9 other heavy 3 shots at a distance where he can only shoot each gun once. A Noise Marine's Blastmaster is also a nice way to pick off Destroyers, particularly since if they run out of range the unit has enough Assault shots at long ranges to still be shooting things most of the time while they're catching up.
