What does The Prodigal Lich Returns reward?

The Prodigal Lich Returns gives Bone Buckler outright.

What level is The Prodigal Lich Returns?

Its level has not been recorded yet; it shows once a player accepts it with the addon running.

No. The quest exists in Classic Era as well.

World of Warcraft: Forever · quest

A quest in World of Warcraft: Forever in Undercity. Recorded by 1 player running the addon.

Level, giver, pay and objectives show once a player with the addon accepts the quest.

Item	Given	Item level	Vendor sell
Bone Buckler	outright	12	1s 53c

What does The Prodigal Lich Returns reward?: The Prodigal Lich Returns gives Bone Buckler outright.
Where does The Prodigal Lich Returns start?: It was picked up in Undercity.
What level is The Prodigal Lich Returns?: Its level has not been recorded yet; it shows once a player accepts it with the addon running.
Is The Prodigal Lich Returns new in WoW Forever?: No. The quest exists in Classic Era as well.

Source: what players running the addon saw in the quest windows; the quest text itself stays in the game. Every quest seen · Undercity