Blast Burn is a Special attack, and it's a Fire type.
Sharko you might be a Normal and Water type, Fire shouldn't be much effective on you

Sharko : KYAAAAAA WATER WATER WATER. *spalsh water into face* gaaahh.. for the thanks that fire wasnt a hell fire..

*Blaze uses Blast Burn on Sharko*

Sharko : ay ay ay ay chill just jk ;)

Blaze : ...I know you were gonna say "Cute" *About to summon a Blast Burn Move*