Counter Invasion!
Currently, the Evil Trio were somewhere around level level 112 of Rank 3, still at the entry level. After all, they gained only 0.001% of all experience, and it was already hard enough for those with 100% experience to rise through the levels regardless of their skill.
Even after killing Rank 7 NPCs repeatedly and by the hundreds, they only climbed like 12 levels. This was also with the slaughter of over 30 million players in front of Vita Kingdom, but that one only contributed like 2 levels out of the 12.
To summarize, leveling up for the Evil Trio was a herculean task. Not to mention that they were three, so whatever they earned was split between the three of them before being subjected to the cruelty of their class.
So the effort they would need to put into to level up was so heavy and herculean that I would cause any regular person to vomit just visualizing it.