WMG / Tactics Ogre

Lans Tartare's real agenda
Warning: this theory uses the plot of Knight of Lodis.

We know the following:

Therefore, I theorize that Lans Tartare's real agenda is to find Eleanor and/or Shaher. His plan was to exchange Eleanor for Catiua.

A Gaiden Game or even a main title game (episode IV?) was going to be about Andoras

My theory for the series was that episode I was the titular Ogre Battle itself, and that the others were about how humans treated the world after they won it, with games dedicated to Lodis's rise and fall amongst other countries such as Xenobia and Valeria. Andoras would have had one game about the Lodissian invasion of his homeland. Honestly, I think They Wasted a Perfectly Good Plot or maybe they had plans with him. Then again though, there's also Volaq - while he didn't have much of a backstory, they really could have done more with him than they did.

Vyce was destined by the Wheel to oppose Denam.
Similar to Jowy from Suikoden II or Fuuma from Manga/X1999. He loses his sanity if the Wheel forces him to be evil.

The Taken for Granite Statues in the Palace of the Dead are backup bodies for Beelzebuth.
Yeah, she says she'll wait until a party of adventurers comes and then kill and possess them; but staying incorporeal is difficult (and there's no reason to tell Denam that.) She'll "soften" one of them and wait in it while waiting; they've been stone enough centuries that the bodies are substandard; and fresh bodies are better; but each one can last a little while.