In Wrath of the Lich King it is item level 245 and requires level 80. In MoP Classic it is item level 245, requires level 80 and sells to vendors for 1c.
In the Appearances collection, Relentless Gladiator's Piercing Touch is listed as Vendor. Appearance ID: 10987. 1 other item wears the same appearance:
Unearthed Staff HeadpieceID 142449 · Consumable"The staff has long since rotted away but power still pulses within the mystical headpiece."
Items Numbered Next to Relentless Gladiator's Piercing Touch
Blizzard numbers items as they are created, so the named items next to ID 42521 (42515 to 42530) were usually added in the same batch as Relentless Gladiator's Piercing Touch: the same quest line, zone, vendor or reward set.