That 'five-headed god' on the top is a new Elona+ enemy, can surprise you with various elemental breath attacks.
Some enemies are higher-evolved versions of old Elona monsters, like this 'quick redcap' (quickling) and 'bell of termination' (bell). The latter dropped a 'caramel of termination' when killed. If I ate it, it would summon the dragon horde and set everything on fire, as mentioned above.
Rather than killing, I dominated the NPC in the lower right. It'll fit right into my new team.
An easier way to get some impressive-looking monsters is to capture one in its lower form (a dragon for this one, iirc) and evolve it into this, with the right item and conditions.
That seraph up there owned pretty much everyone on the field, until it croaked from a timed 'death word' from one of the nastier enemies that survived long enough for its curse to take effect.