Paradisial Flare is the flame that adorns the afterlife's Paradise, and it is beautifully pink. No one can feel its heat, even when approaching it up close. However, any individual who touches it will suffer more damage than the total number of humans they have intentionally killed. That power is truly formidable, and suras who have killed many humans, even nastikas, try to avoid Agni. Other Fire-attribute gods do not have enough offensive power to threaten a nastika.
In the distant past, a planet falls under attack from Gandharva, and the planet's minor gods lament that Paradisial Flare barely did any damage on him. Agni suddenly appears to help out, and uses his more powerful version of the skill on the nastika. The minor gods mention that Agni spent a great amount of time and effort to acquire the flames. They are ready to claim victory, until Gandharva suddenly revives, destroying the planet along with its human population and minor gods. Later on, Brahma reveals that not even Paradisial Flare can kill Gandharva, because someone else took on the burden to pay the price for his sins.
Paradisial Flare is one of the transcendental skills Agni uses in an attempt to provoke Gandharva into pursuing him and abandoning his attack on Kalibloom. His use of this skill was specifically to test the speed of the nastika's regeneration, since he is much weaker than before. We do not learn until Season 3 that the skill cannot actually kill Gandharva.
After Siera Sies becomes possessed by a Taraka, Agni decides to attack the monster in a way that would not hurt Siera if possible. and uses Paradisial Flare. It has no effect, leading the god to conclude that both Siera and the sura have never killed any humans, and therefore the sura must be Shakuntala.