Board Thread:Suggestions forum/@comment-26210095-20150804013857/@comment-26298013-20150807162919

Speed of flow of lava/pyroclastic flow depends on its composition. Lava is absolutely, entirely, and hilariously ridiculous in the Middle Ages.

I agree with liquid fire, however, because we have a basis for it. Or perhaps we could have a liquid fire or just fire-causing item that creates eternal flames. For aesthetic effect, you know. Oh, and also because its fire. And it doesn't need fuel. Or hearth blocks.