Lex had a… difficult… time explaining to Toro what a realm was, though Lex had a sneaking suspicion that the Trelop understood the concept somewhere in the middle of the explanation, but was just venting its frustration on Lex.
When it finally understood, Toro displayed a remarkable amount of 'not screaming' at Lex randomly. Instead, it became silent as it contemplated the ramifications of what it had heard.
The issue that it was facing was not the destruction of its entire world - that was a given based on the situation. The issue was that Lex did not have a solid grasp of the timeline. According to what Lex said, the appearance of the elixir meant that the realm was on the path to destruction, but the fact that it was on that path also meant that it could be veered off that path. The top minds of the realm would think of ways to work on the issue, but it all depended on how long they had.