Mercurial Thrust is a recurring ability in the franchise. It gives the user an immense priority in turn order, often going first.
The hero can use Mercurial Thrust as a spear technique after investing 7 skill points into the associated skill. The skill has received an upgrade under Level-5, and now always goes first turning a turn.
This ability is learned with 3 skill points invested into Spear skill, and operates exactly as it did in VIII.