Dimension Slash Scorching Light

Combo Spell: Dimension Slash Scorching Light (合体魔法『次元斬り 灼光』) is a dark-, mercury-, and fire spirit-based Compound Magic spell.

Description
The mercury magic user extends the length of the dark magic user's blade, then the fire magic user ignites the extended blade with flames from Salamander.

Trivia

 * Even though it combines more than two attributes, the movie used gattai mahō (合体魔法) which has been used for a combination of two spells. Also, the English dub used "combo spell" which is consistent with previous translations of gattai mahō.