Being Human: Digital Arm Concepts

I have farer developed my designs, I am yet to narrow the characters down to three but here are the arm concepts for them.
Joy's concept, a blade that resembles light. To note the mutations are all formed from a material harder then steel.

The arms have a passive state of a regular arm but can be triggered into to its weapon state by the user's emotions.

sadness' concept, The arm looks as it is flowing like water. As the arm can move like liquid metal.

Fear's concept, razor sharp claws with spikes running all the way along the arm as defences.