All the Guardians talk remembered me about Pokémon intro part... Thank God you guys said battles look like Tales of Phantasia battles! I didn't got too far on the game...
Well, the Guadians are just cute companions that helps you out in battle with specials and helps forge weapons with you. It doesn't do the actual fighting.
The whole fun is the random battles are like Tales of Phantasia, all real time like Loash mentioned. You also collect your own materials and formulaes to create weapons that have durability. If you don't maintain them, they eventually break. Also, different weapons are more effective against one another. For example axes are stronger against swords.
Finally, there's the nightly conversations where you can spend some time with any of the main characters you meet to add to the character development.
It's a great series on the GBA although I don't know what the PS games are like.