Why has no one else realized that by explaining his plan to Elan, Tarquin has effectively guaranteed the success of his secondary plans. Tarquin has two major goals here.

1. Rule in power and luxury for as long as he can (Impossible to thwart because it has already happened.)

2. Be remembered as the ultimate villian (certainly seems to be working, judging from the amount of data on this thread )

But seriously, it does seem that explaining the whole thing to the bard makes Tarquin's true story more likely to be remembered.