Here's how to fix morde
give him 2 passives, 1 that lets him build up his shield, and apply at 2.5 sec stun on every fourth ability cast
Q: keep it the same way, but gibe it a passive that doubles his crit bonus, and allows him to hit people from a 600 range, If he activates it again he will dash towards the person who got hit by it.
W: Keep it the same way, but this time allow him to use it to dash towards his allies and wards.
E: Keep it the same way, but gibe it a slow.
R: Keep it the same the way, but gibe it a 200% ad and ap ratio, and allow him for 15 sec to ignore 50% of his target's bonus armor, and give it a new passive that banishes anyone killed by it from the game. Meaning you cant respawn from the graveyard.
These concepts will definitely make morde more viable, lcs bigplays, and balanced.