I use
(Katon: Kasumi Enbu No Jutsu) - Fire Style: Mist Waltz
Rank

Type:Supplementary
Range:Short
Chakra cost:10
Damage Points:N/A
Description: User spits out a huge mist of flammable gas the can be ignited by local fire or by a fire jutsu.
and
Suiton: Kokuun) - Water Style: Black Clouds
Rank:C
Type:Supplementary
Range:Short-Mid
Chakra cost:15
Damage Points:N/A
Description: Creates a down pour of oil rain from the sky that is flammable and can be used with fire jutsu or any source of flame to ignite the oil.
to make the area flameble then I light it all up with
(Katon: Housenka No Jutsu) - Fire Style: Phoenix Flower Jutsu
Rank:C
Type:Attack
Range:Short-Mid
Chakra cost:15
Damage Points:30
Description: Small Muliti-Fire balls that spread out and converge on the opponent.This jutsu can have shuriken hidden in it for added damage.
so the fire is very strong and it burns u