|Use of Collection|
|Magic system||Ancient Belka|
|Japanese name||蒐集行使 |
Use of Collection (蒐集行使 Shūshū Kōshi) is Hayate Yagami's Rare Skill, the ability to use the collection of both Ancient Belkan and Midchildan spells at full performance. It is inherited from Reinforce (originally from the Book of Darkness) after her self-destruction. It is not detailed, however, whether this Rare Skill includes the ability to collect new spells.
When possessed by the Book in A's, Reinforce (as "the will of the Book of Darkness") is able to wield all the power of those whose Linker Cores the Book has absorbed, including Nanoha Takamachi and Fate Testarossa.