Thunder Fragment

Found in

Loot table	Quantity	Drop rate
Lightning Key	1	0.047% (1 in 2,130)

Chance per kill, from the game's loot data: one loot pass on an unscaled map. Party-scaled instances roll the same tables again, so these are floors, never ceilings. A rate marked "at least" is one whose roll count depends on data this wiki does not carry.