|Primary caster||Fate Testarossa|
|Japanese name||アークセイバー |
|First app.||Nanoha (ep.4)|
Arc Saber (アークセイバー Āku Seibā) is an unusual shooting spell which can only be used while Bardiche is in Scythe Form. It consists of throwing Bardiche's compressed mana blade at the target like a boomerang. The attack is fairly powerful, as Fate uses it to great effect during her fights against Nanoha.
Although the range is only middling and the projectile speed is not high, it can "bite" barriers and its varying route is more difficult to defend or dodge. Because of this, Fate can use the spell to trick her opponents. In addition, the energy blade can also explode at any time with the keyword "Saber Blast". In The MOVIE 1st, the keyword is "Saber Explode".
- Haken Saber (ハーケンセイバー Hāken Seibā) is the spell that replaced Arc Saber after Bardiche is upgraded to Bardiche Assault. It can only be used under the Haken Form.