No easy prey
The suit of armor struggled with all its might, but the grip Lex had around its arms and torso did not let it muster much strength. It used various techniques, but since they were mostly fire based they did nothing to Lex.
Lex had not figured out how the suit of armor made a clone and disappeared despite the fact that it had repeated the move a few times already, but Lex had figured out that as long as they were touching, the technique wouldn't work.
So despite all its effort and resistance, it turned out to be nothing more than its dying throes - or it would have been if Lex continued to use the technique the entire time. Space Warp was extremely expensive in terms of energy consumption, and he could not keep it active for more than a couple of seconds.