Going to repost this from another post since several people (for some reason) have been posting the same question:

You need certain ninjas like samui, omoi, and darui to work with him and if you aren't willing to switch to a certain class (lightning or earth), don't bother. If you want to know the usefulness between 3rd raikage, susanoo sauske (normal version and skillbroken version) and 4th raikage (normal version and skillbroken version), there has been discussion about him: https://forum-narutoen.oasgames.com/page/show-post-25044-1.html

Because you can build a ready-to-go team with samui, omoi, and 3rd raikage if you were to switch to either of the two mentioned classes, there is some value to that for those who aren't able to create the lightning roshi team or a strong earth team.

If you were to look at his one of his passives since you can do that if you search his name in ninja interface, it says for every 1 charka point, he get +1% ninjutsu + attack and 2% defense. This means if you have 50 chakra, ay gets a 50% buff for attack and ninjutsu and a 100% buff for defense.

Yeah I know that. That's why 3rd is paired with samui