Rending Power Weapons - Why? Well...

"So, someone please help me through this as im either missing something or found something which doesnt make a ton of sense. As my army (1500 pt) will be led by Shrike, I was reading he has master crafted lightning claws (2x) with rending. Great, I get to re-roll a missed hit and wound(s). His lightning claws however also have the rending ability. As I began to think about this, what does that really matter? Lightning claws are already power weapons, so you arent conferred a save from then anyways (which is what rending does, blocks a save). Now, rending also give an extra d3 armor pen, but who cares, he is S4 (not going to get into that rear armor value of 10 anyway). The only case I can see it really having ANY value is if I attack something with Toughness >7, which a 6 will still wound (when normally S4 cant wound T8).

Am I missing anything?"

Well, it seems like I DID miss something.

I was thinking over the issue (along with some help from dakka dakka and the dice like thunder forums) and yes, Shrike basically gets a guaranteed pen hit on a av 10 with a re-roll to hit, re-rolls to wound (I simply forgot how armor pen works, duh)... Now my next question im looking into, If he infiltrates with my TH/SS assault termies, and lets say im forced to start 18 inches away, is it worth letting him run out on his out with his possible 19-24 inch assault range and let him jump on those Leman Russ tanks himself... I only say this because the terminators threat range is anywhere from 13 to 18 inches, so they may not get the coveted first round assault (if I can hide them, I can infiltrate 12 inches away), but they still benefit from infiltrate.

Thanks for helping shake the rust off, its been a while since Ive actually played the game given im building the RG and Ork Boys armies. I hate to play with unpainted models and painting assembled models is a pain anyway. Lastly, what the heck are those tiger claws in the picture I attacked, seems like a rather nasty ninja weapon or something along those lines.

Correction - Shrike doesnt get to re-roll against vehicles, since he isnt rolling to wound. Thanks for the comment DezartFox.

Correction #2 - Apparently, there is a heavily heated debate on whether Shrike can infiltrate with a non-infiltrating unit. It sounds like RAW says no, however RAI or the GT faqs ruling say yes. I think he can, however it sounds like until the FAQs address this its up in the air... Leave your comment! And please please dont go into rule rundowns, there is plenty of that here: http://www.warseer.com/forums/showthread.php?p=3841122