OK ... maybe its easier for some of you out there, but it isn't for me ...
there are some things that i cannot do !! one of them is grabbing an enemy 10times in the air with kulshedra ... i frigging can't do that !
There's an Alfheim portal where you have to stay in the air for 20 seconds. It's the 5th one and it's in Chapter 3 after the verse 1 battle, near some benches. Basically, equip the Kulshedra, lock on to an enemy, jump and hold the punch button. You'll grab the enemy and pull them towards you. Once you do that, push the stick in the direction of the enemy and jump off them. After that, lock on, hold the punch button and repeat. It doesn't have to be the same enemy, just as long as you grab something and you grab at least 10 times in total without hitting the floor, you'll be all good. Also, if you mess up the Alfheim, you can repeat it again as many times as you want.
If you can't get the jumping kill one either, you do the same thing, but only equip the Lt. Col. Kilgores on your feet. When you jump off an enemy, you'll fire rockets as you jump, killing the enemy you jump off.