Knight of the White Tower
The City of Corsairs#139 (x3)
Ally
[4] 2 2 3 3
Knight of the White Tower's resource cost must be paid from a single hero’s resource pool.

"...to be only a man of arms of the Guard of the Tower of Gondor is held worthy in the City, and such men have honour in the land." -Beregond, The Return of the King