Lower gauge kanthal (28 gauge) - twist it if you need to. .25ohms is some pretty lofty territory - hope you like replacing
batteries as that is only .25ohms away from a dead short (it's a battery killer). Considering that most of the 3.7volt
batteries are around or slightly above 4 volts when freshly charged - that's 64watts at 4 volts. Do you really need 64 watts? Most folks are getting a real nice
vape between 7 and maybe 12 watts. Sure - some go for the megawatt stuff, but I doubt that those are all day vapes.
Do as you will and enjoy - but .8 ohms at 4 volts is already 20 watts.