Any advice for scaling final Storm King’s Thunder encounter for 5 Level 15th PC’s?

Is there any lore about why Titans are no longer at the top of the ordering?

There is an official answer to who pillaged Morgur’s Mound?

Where are the named characters in the Storm King’s Thunder minis from?

Forgotten Realms Eastern Cormyr and the Purple Dragon, any suggested readings?

Storm King’s Thunder encounter difficulty is out as beyond deadly!