Grailseeker is the 33rd most-used weapon under the current filters (0.8% of 357,008 recorded fights), winning 53.2% overall - 11.5% of its wins come against better-geared opponents.
Best against Great Nature Staff (91.7%), Fire Staff (77.2%), Cursed Staff (74.4%). Struggles against Arclight Blasters (10.0%), Demonic Staff (13.0%), Crystal Reaper (15.0%).
Winrate by IP difference (50-IP buckets, dot size = sample size). A flat curve means the weapon carries regardless of gear; a steep one means it only wins when out-gearing.
