Flamethrower??

[Ravendust]

For you confused people: Trunks wasn't the only person to use it. The "flamethrower" was used several times by several people throughout the series. A few examples:
-Dabura blowing Kibito away after the gang discovers Babidi's hideout
-Goku blasting Brolly at close range in movie 8

And others that I forgot.

Vegeta owning Pui Pui was the 'other' memorable one

 

[Skiwan]

vegeta did it to 3 different people in the saiyan/namek saga too... not to mention piccolo doing it to frieza, and goku using it at various points, and gohan during the namek saga (methinks..), and cell did it too... and buu did it as well.. imo thats pretty generic >_> i suggested implementing close range ki attacks but peoples ignored me :'(

But im sure flamethrower will be great