As said above; Lightning Claws are designed for shredding through light/medium infantry, which is basically anything with a 3+ or worse non-invulnerable save, like you were Wolverine on a rampage where as the Chainfist is used for carving through armoured bulkheads inside of Space Hulks and buildings or for cutting very large holes in tank armour to get at the squishy crews inside.
You were thinking of Tiberius, the Red Wake of the Carcharodons (Space Sharks) chapter. They're very cool. On topic - like others said, they fulfill different roles. But I prefer lightning claws!
they are fu***** brutal I bet they use these as tactical knives in the end they were world eaters or raven guard descendants?
Another reason for the Energy Claws, if you wear them as a pair, you have two attacks. But I prefer the Thunderhammer, size does matter. And if you hit a Tank the crew is shaken.
Lighnint claws are alot cooler and usually used by Assault marines/raptors since they can basically just swing their hand around and rip people apart or grab/impale them. I think they are genrally a better close combat weapon since they are faster and more viable
when i heard of the chain-fists i thorough they where a lot cooler then they really are. So i am going with lightning claws
