Subverted in BIONICLE, in which Tahu defends himself from Nektann by using his fire powers to soften most of his enemy's armour off and incapacitate him - but producing a distinct point of not killing him in the process.
Schlock's plasma cannon emits large amounts of higher-temperature plasma, enough to melt via deck plates. Dwarf Flame Cannon and the Skaven Warpfire Thrower.