Now there have been plenty of suggestions that the Shredder become our flamethrower, but I am not entirely convinced on that front. It's a valid suggestion, but I think that maybe we can look into other options for it.
I will note upfront that this isn't a thread where every suggestion is considered to be the be all and end all in and of itself, merely spitballing ideas that might be further refined and reused later.
So, my thoughts.
1: The shredder needs monofilement rule, like all other eldar monofiliment weapons.
Concept one: Rapid Fire Shredder.
Given a range of 18" and a rate of fire of Rapid fire d3, the Shredder becomes a really nice if somewhat random horde killer. at short range it puts out a good number of high strength, shredding wounds and is potentially AP -4 due to monofiliment after that is done. Not something to sniff at, and a squad of these will annihilate light infantry.
Concept 2: Entangling Shredder.
The shredder functionally fires monowire net grenades, more or less, so why not give it some debuffing power? Keep it as is, add monofiliment, and give it a debuff that units that take an unsaved wound from a shredder cannot advance next turn and are at -1 to hit.
Concept 3: Flexible Shredder.
Upgrade its basic range to 18" and give it monofiliment but otherwise keep the mainline shredder as is. However, add a secondary firing mode with is a 6" range assault d6 auto-hit. Effectively, it does what it currently does and it doubles as a short range flamthrower, making it a tactically flexible weapon that can be used for midrange bombardment or close range devastation.
Subject: The Shredder. 
Sat Sep 16 2017, 02:25
