"Elves of Misty Valley" is episode 96 of the Berserk manga series.
Summary[]
The tree groans out the word "Sacrifice", confusing the young girl but eliciting no reaction from Guts. The tree attempts a pincer movement with its branches, striking from both the left and right. With two fast swings, Guts cuts them out of the air, then leaps away with blinding speed. With complete composure, he dodges the onslaught of oncoming branch strikes until he runs straight into a well-placed bunch of branches, trapping him mere feet from the tree's main face.
His head slumps down as though defeated, but Guts has a manic smile on his face; he's jammed his metal arm right into the tree's face's mouth. He pulls a metal switch on its side, and the metal hand flips down below the arm, revealing a wide hole in the forearm. From this hole, a cannonball bursts forth, blowing out the entire back half of the tree. In the same moment, Guts has readied his sword and brings it down on the monstrous plant, cutting it clean in half.
The young girl watches the entire scene in awe and horror. She stares at the destroyed tree, from which small spirits emerge. Guts, whose last sword swing's momentum sent him tumbling onto his back, looks up at the sky, where the clouds part and the sun shines through. He has not seen the sun for three days.
The rays of sunshine touch the spirits, making them slowly dissolve into thin air.
The elves' leader.
Another spirit, still incorporated into the tree's bark, frightens the girl, but a chestnut shell is dropped onto its face by a small elf, the reluctant Guts' companion, Puck. She screams in terror at the elf and claims that he's from a place called the Misty Valley. Neither Guts nor Puck seem to have any idea of what she's talking about.
Deeper in the forest, the surviving bandits run for their lives, further and further from the demonic tree. Just as they begin to feel safe, a thick mist forms around them. One of the bandits points directs the leader's attention upward, toward the forest's canopy. High above them, dozens of what appear to be elves are flying this way and that, leaving trails of light in their wake.
Their leader is seemingly an elf, though compared to real elves she is gigantic; she is the size of a young girl. She has moth-like antennae and eyes, with wings to match. She is also capable of speech, and she tells the bandits that they have stepped into a child's fairy tale.