Despite its appearance late in the raid, Shadowstrike has an extremely low item level, low speed (and thus low damage), and its proc is not particularly valuable. Because it is outperformed by blue weapons, it is frequently nicknamed Vendorstrike or Nexustrike. It can transform into a separate weapon, [Thunderstrike], which suffers the same issues.
This item was mentioned in the April Fools' Day patch 22.214.171.12409 notes: "It's been almost 15 years and [Shadowstrike] still reminds you of that one polearm nobody wanted in Molten Core."
Patch 1.11.0(2006-06-19): The cooldown on transforming this item is now always 60 seconds.
Patch 1.8.0(2005-10-10): Shadowstrike and Thunderstrike will now remember the enchantments and durability data they possessed when they transform.