Winters then grabbed a small bucket onboard, placing four metal containers that were emitting thick smoke inside and used all his strength to push the barrel into the water and towards the shore.
Through the standard spellcasting materials provided by the Magic War Department of the Alliance, the Alliance's spellcasters could reproduce the "Smoke Spell" effects of the Imperial Court Mages.
Winters didn't know what was inside those metal containers, which contained precious alchemical products. He only knew that releasing a fire spell on the substance inside could create thick smoke, and that was enough for him.
Swordsmen don't need to know how to forge swords, and spellcasters don't need to understand alchemy. Users don't need to know the principles; they just need to know how to use it.
The full name of these metal containers was "Trigger-type Portable Activated Alchemical Substance Smoke Generator," but the officer spellcasters simply called them "Smoke Grenades."