Jeffrey was a level 4 Earth Immortal. It wasn't the highest, but it took him years of effort to get here, moving from one realm at an excruciatingly slow pace. The progression was so slow, it was torturous, which is why he liked torturing others as well. Why should he be the only one to suffer?
Yet never before in his life had he ever suffered the way he was suffering now! Lex was insufferably strong even before he became an immortal, to say little of when he actually gained an immortal physique.
Moreover, he was already proficient in manipulating laws! That was not an ability immortals just gained! They had to train and practice for it! Jeffrey himself took over 70 years before he could successfully manipulate laws.
It was not without reason that most immortals that Lex encountered did not use too many laws against him. It was because they weren't good enough at it to use in a fight!