A little information before hand, I am DM'ing a campaign with a necromancer Kenku, a barbarian that is a complete bitch, a bugbear barbarian who can kill with a single backhand, a half-orc fighter, and a high elf homebrewed jedi.
And of course the issue comes from the fucking Kenku.
One of my players, the Kenku, went into a tavern of 8 soldiers and was trying to use suggestion on a few NPC's, who weren't weak but weren't the smartest. Everyone kept beating his DC except for one. He convinced the poor shmuck that the guy on his right was stealing from him.
Suddenly one of the soldiers noticed the spell he was using and smacked the shmuck out of the kenku's spell, upon which the one who noticed glared at the Kenku.
Kenku player rolled bluffed and succeced. After success the soldier went back to drinking but the kenku gave said soldier a tightly closed piece of paper with a sigil on it.
Player was playing coy in order for me not to find out what he was planning.
After a confusing exchange, the soldier was unaware of what the paper was capable of, and in order to test it he opened it pointing it at one of the other NPC's in the bar. What came out of the small piece of paper was a fear spell. Out of eight soldiers only two did not go into a frenzy, a general and an excessively powerful soldier, the other six went into a fear frenzy and started killing one another.
Kenku player bolted immediately out the back while the general and the powerful soldier went out the front, upon which, after the bloodshed, only one soldier remained. In shock and terror he left out the front to where the other two who fled, who swiftly decapitated him in a panic.
Afterwords, more soldiers came and took the general into custody for instigating the whole thing. After being questioned, Kenku Player denied everything.
Fucking nat 20 deception roll.
One soldier went to investigate the bodies, the kenku decided to 'help him out.' The Necromancer Kenku stole the souls right under the nose of the soldier investigating the bodies and got off scot free.
We're pretty sure he's gonna be our big bad in the end and blow up the world.