Well, maybe a Swooping hawk grabbing at the wall and all that...is a bit logical, but a power-armoured brute!? With extra weight of Jump Pack he's completely unlikely to be able to find something sturdy enough. Too heavy, you know... Unless he's a CSM Raptor with all the HUGE CLAWED ARMS AND FEET mutation epicness
Aside from Eldar (and *maybe* Tau) all the jump packs in 40K are barely controlled giant engines or rockets strapped to someone's back. Personally, I hope that jump infantry that jump into obstacles/walls/trees/etc take some sort of collision damage as they do on the table-top difficult terrain. They arn't agile enough to dodge a tree, they certainly arn't agile enough to land and then perch on the wall, when one or both hands are also involved in holding weapons.....
Grab onto walls? Like hanging from a pillar or something? Wouldn't make sense for an assault marine to go all Batman like that.
i would love climbing abilities for non jumppack units more like standing infront of a 3-4m high wall press "space" he jumps and grabs the edge and pulls himself up
Because of the mutation, they have long and very sharp claws. They dig deep into the wall and thus offer better grip.
I think jumping is not very usual for Space Marines. I think they are to heavy, a Space Marine is around 7 or 8 feed tall, and packed with genetic upgraded muscles. I guess a SM weights around 200 kg excluding his armor. I think with his armor it's about half a ton. It's something for the agile Eldars to jump around.
