What is the relationship between Ultraman Gaia, Ultraman Dyna, Ultraman Tiga and Ultraman Mebius?

Hello, I am happy to answer your questions.

First of all, Tiga, Dyna, and Gaia are all works from the Heisei era, and are collectively known as the Three Heisei Brothers (Heisei Three Heroes), among them, Tiga is the first of the Three Heroes of Heisei. He is a giant of light on the earth. He has an age of 30 million years and represents the light of love. Dana is the nominal younger brother of Tiga and represents the pursuer of courage. Gaia is the last of the Three Heroes of Heisei and represents the power of unity. In short, these three Ultraman are different from other Ultraman in that they do not come from the M78 Nebula but from Ultraman Qiu (accurately, they can only be called Giants of Light)

As for Mengbi Yus is the younger brother of the first generation, Zoffy, Seven, Jack, Ace, Taro, and Eddie, and is the apprentice of Zoffy and Taro. That is, Mebius is the return of Ultraman in the Showa series. He is Ultraman from Nebula M78, so he has no essential connection with Tiga, Dyna, and Gaia. Thanks.