no! its not. as long as you can "fake" the allusion or make the flames ur fine. Ive seen some great cosplayers just buy nude bras that are their skin tone then make the bathing suit on top with just black fabric.
Adelheid (KHR!)- 85% done
Fem!Austrian War Succesion France (Hetalia/Nyotalia)- 10% done
Fem!Izaya (Drrr!)- 90% done
Magent!Teto (Vocaloid)- 95% done