IMPERIAL BODYGAURD: At the beginning of the game, choose a friendly character. When that character is adjacent to Caiera, that character's defense value becomes 18.

I have a question about Tournament play using Caiera.

Does the friendly character need to be the same in every game played in one tournament or can you choose a different character for each game in a tournament?

I ask because my opponent's team or map choice may determine who I want her to defend.

It can change from game to game.

The text answers the question, at the start of the game, every game

Thanks, for the quick answer.

I have a somewhat related question:

If I pick Bruce Banner to be the bodyguard and he AE's into the Hulk, does the bonus transfer?

Yes, transforming a character via AE is considered to be the same character, or at least continuous from the character. It will also keep any feats or other game effects targeting it.

The only time a bonus would not transfer via Alter Ego is if the prerequisite for the bonus changes.

Such as Keywords, if you have a Theme Team and you switch a character and that character no longer has the Keyword, that character would no-longer be able to do TTProb.