The THUNDER FIST is a move that involves punching your enemies with lightning, this move is difficult to pull off as you need very good timing. If done correctly you will shock them and/or launch them across the map, the shocking one is more common.
(I believe this is possible because of glitch in where the game isn't sure whether you are punching or using lightning, thus making both happen at once.)

To use the THUNDER FIST you must select the lightning spell from the spell wheel, to do this you must open the spell selector and select the lightning spell.
Congratulations, you are now ready to use the THUNDER FIST.

STEP 1: To use the THUNDER FIST you must press the correct buttons at the same time in the correct order, the grab item which is the side textured button on a Vive, and the spell button, the trigger on a Vive. This will form a fist, you may use this normally to get a feel of B&S's fist fighting and proceed when you are ready.

To release and ultimately attack the enemy, you must release both at once, if done correctly you will see lightning come out as you release the buttons. Timing is key in using the THUNDER FIST, you have to punch them and release at the same time. It is recommended to use slow motion to time the punches correctly.

To get maximum coolness, it is recommended that you shout "THUNDER FIST!" as you attack your enemies, this will make you the coolest Blade & Sorcery player to ever exist.

The THUNDER FIST only half works in U8 because of the way spells work now, you can sort of slap people whilst using the lightning spell, so I shall rebrand this to the thunder slap.