Basically just a butler
It actually made sense that Lex could so easily handle an immortal. His own strength was as such that he would immediately initiate the tribulation for the next realm if he hadn't kept his powers sealed. Thinking of it that way, what that meant was that he had already reached the power level of the next realm without actually entering the next realm.
But even if he was at that level, destroying someone's tenets using brute force wasn't something Lex could achieve. Unwilling to keep this farce going on for much longer, Lex immediately used Space Warp.
This was an ability he learned long ago which allowed him to bend space in a region as he wished, causing a massive spike in gravity. Considering the fact that he warped the space inside the immortal's soul, he finally managed to break his tenets.