Ishura

Both feature a numerous and diverse cast of individuals wielding immense power engage in one-on-one battles, but the majority of screen time is spent on introducing and establishing the combatants character, rather than on battles themselves. In other words, these are Battle Royale's that focus on fighters instead of their fights. 

It has its own well designed world and real politics like in Shingeki No Kyojin. There are lots of characters and each have their own unique aims and plots. Story is deep and complex and there are lots of mysteries beautifully revealed. Whole fight in this series are enhanced with amazing strategy and realistic dialogues. 

Both are shared unique characters Both are shared the fight that can't be avoid Both are shared the happiness to us Fun 100% 

If its enough for you to go off of, then similar vibes. Both have a sort of darker adult motif, where there is something going on behind the scenes but you aren't sure what. And a bunch of strong people are isekaied to this world and fight... for reasons. 

This is only based on my impression from watching episodes 1-3 of Ishura. - Both series have similarities where the Demon God/Lord has influenced the world - Both are, per say, looking to be the "best of the best" - Both have their own "character background" that we need to further explore as far as the series will go