Jigadiras Uru Zakeruga is Zeno's strongest spell. It summons a massive, winged goddess with a crystallized cannon-shaped body. It charges itself by lighting up the five lightning symbols on the sides of its cannon opening and releases the energy into a tremendously concentrated Zakeruga blast.
Zeno calls this spell "The Lightning God of Destruction" and is the "fruit" of his power he worked for, implying that it is a spell that he himself developed, similar to how his father developed Baou Zakeruga. It is so strong that it managed to defeat an, as-of-then, unmastered Baou Zakeruga from Zatch. The spell is blocked by Tia's Chaajiru Seshirudon.