Murk Strider - help, please

Bubbleworks

How does "process" work? 

The card says: When this card enters the battlefield, Process 1: if your opponent has 5 or less cards in their hand, return target creature opponent controls to their hand. 

I can't figure out how to trigger that and the card doesn't have an explanation. 

Thésée

Process is more a requirement than an ability. Process 1 means that you need a void gem on the board to trigger the ability described 

Void gems are empty, colorless gems created by cards having the Ingest ability 

Ingest alone is a mechanism that can be cool. Cards like Transgress the Mind or Grip of Desolation have a powerful effect, plus they ingest, meaning you get rid of one gem of the colour of your opponent. 

But Process is weak since you have to build your deck around Ingest cards to be able to use the cards with full effect. Even at the time of Battle from Zendikar there were much more powerful options 

Bubbleworks

Perfect, thank you!! I have cards with Ingest as well and that was my next question. :-)