Imagine a baby tried to stab you with a leaf?
In retaliation, do you kick it out a window?
It's like Jack Palance in that old cowboy movie Shane. He's the greatest gunfighter in the west. And this farmer is getting mouthy about Jack's employer bankrupting his farm (????) so Jack throws his spare gun on the ground and says like "Pick it up. I said Pick it up... I can't kill you until you pick it up."
Merlin just told a Dragon to wipe out an Army.
Then killed 20 men with a wave of his hand.
Agravane, by some miracle survived both those attacks and he's barely standing surrounded by the fallen corpses of his... "Friends" but golly, he's got a KNIFE!
Did Agravane commit suicide?
Seriously it's like getting into a fist fight with an on coming train.
If you're in a fist fight with an oncoming train, do you really want to throw the first punch?
Agravanes only recourse at the point wasn't even to run, Merlin was in a foul mood. Those asshoes attacked his home and his mommy. Agravane's only recourse was to surrender and swear allegiance to Merlin.
Not Arthur.
Merlin.