There is no "evil slave". The faithful slave Is the evil slave, should ne be unfaithful.
"On the other hand, that servant, if he is wicked, may think that it will be a long time before his master comes." Matthew 24:48 GWV
But if the man, being a bad servant, should say in his heart, ‘My master is a long time in coming,’ Weymouth
But if the slave is bad and says to himself, ‘My master is going to be gone a long time,’ - Williams