Farming with Sphere Parasitism (Damage builds)

Hi Guys. I'm Level 80 and the strongest monster I can one shot are eggyras using converters (no longer need amistr and food buffs but I used to need it). I can still farm eggyras for zeny and selling evil horns but I want to prepare for a possible next step.

What's the most farmable monster you can one-shot and what's your build to be able to do that?

Edit: I think the next most farmable monster in terms of HP and spawn rate are minorouses with 27K HP. Is it possible to one shot them?