A lone madman

You watch bewildered as a human wearing a black hood slowly marches up the path. Why was he moving so slowly if it was just him? You creep closer and listen to him mutter to himself.
“Fools, all of them,” he rasped beneath his hood. “Yes, fight the monsters, fight them for me. I’ll just follow behind unnoticed. Pocket all those precious treasures, yes I will. No need to thank me, I’ll thank myself when I pocket the coin from selling the shinies, yes I will. I’m the bestest thief there is, I is.”
You couldn't believe your ears. You always thought heroes were a little crazy, but you never expected to encounter one so clearly insane. Didn’t he know that you get zero experience from opening chest and pocketing loot? If this was his strategy, he would barely level at all. You snort, no way someone was actually that stupid. He turned to look right at you.
“What’s this? A little monster thief come to steal my shinies?” Again with calling you little, “Well you can’t have thems. They be my shinies. Mine!” He brandishes a long knife. “Does the little monster have treasures of its own? Me thinks it does.” He takes slow deliberate steps forward. You wonder why he doesn’t advance faster. As a rogue his strengths lay in speed and agility, not brute . Then it hits you. He can’t move faster, the greedy little bastard was encumbered with too much loot. You grin and advance just as slowly, flail whirling. When the two of you are almost, but not quite, closed you lunge. Your true speed catches the rogue of guard and your flail slams into his hand.
“Yeowch!” He drops his knife and hops about waving the injured limb in the air. “Nasty little monster hurts me it did. Well I’ll just have to hurts it back, won’ts I?” He bends over to retrieve his weapon. You had no intention of letting him do so. You bring your flail down on his head, knocking him to the ground. It only takes two more blows before he dissolves, leaving behind a small pile of loot. You were certain he was going to be pissed when he respawned, most of his inventory gone.
Then, to your surprise, you hear a soft ding. You just leveled up!