One sword in your possession becomes a dragon slayer or giant slayer (DM's choice) for the next 9 days. The charm then vanishes from you and the weapon returns to normal.
Charm of the Slayer
RewardDMGp. 2282014
Raw data
{
"name": "Charm of the Slayer",
"page": 228,
"type": "Charm",
"__prop": "reward",
"source": "DMG",
"entries": [
"One sword in your possession becomes a {@item dragon slayer} or {@item giant slayer} (DM's choice) for the next 9 days. The charm then vanishes from you and the weapon returns to normal."
],
"reprintedAs": [
"Charm of the Slayer|XDMG"
]
}