If you could bring a Gamera series kaiju into the Godzilla series, or vice versa, who would you pick and why?

If I were to bring a Gamera series kaiju into the Godzilla series, then I would bring either Barugon or Zedus in. I would bring them in as they would fit perfectly into the films. Their designs match that of similar kaiju and so would not look out of place, whereas a kaiju such as Iris would. It would be interesting to see Barugon go up against Godzilla, considering his only weakness is water. I could imagine Godzilla grabbing Barugon's extended tongue and then breathing his atomic breath down Barugon's throat. Watching him go up against Zedus would also be interesting, though Zedus doesn't really have anything to make him stand out from other Kaiju.

If I were to bring a Godzilla series kaiju into the Gamera series, then I would bring in kaiju such as Destoroyah and MechaGodzilla, though I'd adapt him to be a MechaGamera. I would also like to see Gamera go up against King Ghidorah, Monster X, 2004 Gigan and the MUTOs. Destoroyah would fit in very well with the other Gamera kaiju, especially the ones from the 1990s trilogy. Gamera has proved himself capable with his amazing abilities such as his stomach laser beam thing, so I'm sure he'd put up quite a fight before either winning or losing. A MechaGamera would be a fun idea to play with, and I'd love for it to be able to easily replicate Gamera's attacks, he'd be a very worthy foe. While Monster X may stand out when put amongst the other Gamera kaiju, I'd like to see how Gamera deals with such a fast moving agile kaiju. King Ghidorah is rather self explanatory, while I would like to see him face the MUTOs and 2004 Gigan just because it'd look awesome.