Concussion Weapons
Concussion weapons are the primary blunt weapons of the Leagues of Votann. Whilst they may look superfluously similar to power weapons, instead of relying on power fields, they utilize mass drivers in order to increase the force of blows. For those uninitiated mass drivers electromagnetically accelerate objects; thus presumably Concussion Weapons are essentially the melee equivalent of Railguns.
Variants
Concussion Gauntlet
The standard finger-pointer of doom.
The equivalent to the standard Power Fist and the most common variant of Concussion Weapon, being used by Hearthkyn Theyns, Einhyr Hearthguard and dual-wielded by certain Chthonian Beserks. Despite the name, being punched in the face by one would do more than just 'giving one a concussion'.
On the tabletop they are Strength +3, AP-2 and Damage 2, lacking the Power Fist's multiplier effect in exchange for having no penalties to hit. Dual wielding them gives the Beserks an additional attack for twice the punchy power.
Mass Gauntlet
A stronger version of the Concussion Gauntlet used by Kâhls.
Whereas the Concussion Gauntlet would be the equivalent of being hit with a power fist, the Mass Gauntlet would be the equivalent of being hit in the face with a Railgun. Given how these weapons work, it would be like turning the target itself into a projectile for a gauss weapon. Punch and watch those poor bastards fly.
On the tabletop, they function as Concussion Gauntlets with an additional point of AP and Damage, but in return having the same penalty to hit as a Power Fist. Still the quintessential One Punch Man.
Concussion Hammer
A hammer Concussion Weapon utilized by Einhyr Hesyrs which are like the Theyns for the Einhyr Hearthguard. Looks somewhat like a Mass Hammer, but much weaker in power.
These hammers are comparatively small in contrast to the much larger Concussion Mauls; trading pure mass for ease of handling. In response, the Concussion Hammer functions basically like a one-handed Thunder Hammer, pretty fucking cool.
Tabletop wise they are Strength X2, Ap-2 and Damage 3, but with a -1 to hit penalty. Hearthguard Hesyrs can pay 10 points to grab one of these. Behave somewhat like a weaker Mass Hammer.
Concussion Maul
Large unwieldy, two-handed hammers used as mining tools by the Chthonian Beserks but easily repurposed for warfare due to their sheer strength.
As a piece of mining equipment, they prove useful in shattering boulders and minerals into smaller, sizable chunks. This capability works just as well against Terminators and other heavier vehicles too. It is the standard-issue close-combat weapon for the Berserks since they are obviously civilian tools retrained for war.
Statwise they are the same as the Concussion Hammer, albeit hitting harder due to the Cthonians' superior strength which generates an extra AP. Beserks can replace their Plasma Axes with this, and if you want to smash anything lighter than a Land Raider into paste you can't go wrong. However, beware that you'll be hitting on a 4+.
Mass Hammer
An even more powerful version of the Concussion Hammer that is only used by the Einhyr Champions.
If the Concussion Maul is a civie tool turned weapon of war, then a Mass Hammer is a purely military weapon meant to make superheavy tanks bend over and cry. If you remember the scene in the Horus Heresy of Vulkan batting away tanks with his hammer like he is in the world's worst baseball league, think of a Mass Hammer to work essentially like that.
Tabletop wise they are the heaviest hitting of the Leagues' melee weapons, being Strength X2, AP-3 and Damage D3+3, keeping the same penalties to hit as the Concussion Hammer and Maul. A 10 point upgrade for your Kahl, this hulk hand is perhaps best used to smash up light vehicles or marines.