Congrats on completing the game, Dragon2005! Yep, that final battle is pretty boring for just about everyone... unless you forgot to get those weapons quenched in black fire
What Wyv is referring to is that you can start the game over with your current characters. Go into the main menu and click on Reset Adventures. That will clear certain quest items out of inventory and put you back in Valeia, ready to hear Gareth's speech again and start all over. It's a way to try out that zenmaster and valkyrie, and can be a bit of fun.