There are many different ways to say "setting fire to" depending on the context and level of intensity needed. Some more neutral synonyms include "igniting," "lighting," or "kindling." However, if a stronger tone is needed, phrases like "starting a blaze," "enflaming," or "incinerating" can be used. For a more deliberate and intentional meaning, words like "arson," "pyromania," or "torch" could be utilized. Alternatively, for a more poetic or metaphorical expression, phrases such as "casting flames," "dancing with the fire," or "painting with the embers" can be used. Overall, the synonym chosen depends on the context and desired effect of the communication.