MOD for How many creatures will die ?

[Keneth]

atom_spawn() function does what it says, it spawns an atom (in your case effect_rampage.atom, first two numbers are target and delay), these are usually animations, effects, or creatures. Unfortunately there is no comprehensive reference (not in english anyway) for the functions, so the best you can do is learn by example.

If I were to guess, I'd suggest that you try Attack.arena_text(string). It's as good a place as any to start. Here is a reasonably well detailed reference of the functions in russian if you're feeling brave enough to read it. Other than that, you'll just have to scour the LUA files.