burn mobs around the player [SOLVED]

Under whatever trigger you want it to be (when item in inventory tick, when right clicked with item, ect), you can have it set fire to the closest entity in a radius simply using the "Get nearest entity at X: Y: Z: in square cube with side (4) of type _____".
But I assume you mean all mobs in the radius.

This'll be a little trickier, but one way you could do it is by having it run a command like "effect give @e[distance=0.01..5] mod_id_thing:CustomPotionName", and then have said custom potion do nothing except set entities with the potion effect on fire. By putting a "set entity on fire for ___" in a procedure triggered by the start of the potion being added. It could then be set to be an instant potion, and/or remove itself right after setting an entity on fire by having it run a command of something like "effect clear @e[limit=1] mod_id_thing:CustomPotionName".

Though, This might be more complicated that it has to be.

You will be able to do this in 2020.5 with this feature: https://twitter.com/PyloDEV/status/1310899869645709317

@Klemen where is entity iderator

nvm i found it