TenSura S2 Pt 2 Ep 6 highlights more world building with regard to the Demon Lords and what surrounds them. It's rather curious for a 2nd cour to be a more setup for what will occur in S3.
Here we are introduced to Demon Lords Guy Crimson and Leon Cromwell. It's made very clear alongside Milim, Guy Crimson are flat out the strongest Demon Lords. The slight comment that Leon would only beat Guy in 1 out of a million times, showcases the power difference he and Milim posses. But considering the respect Guy has for Leon as compared to Clayman whom he views as an insect, perhaps implies the difference in strength between a true Demon Lord and a regular one.
The other added part that is introducing is when Guy mentions he is no longer human. But when Leon went from being a Hero to A Demon Lord, did he also give up his humanity? And how?
The subject of Veldora being back, is a hot topic like it was back in Tempest. We do learn that the Silver hair woman is Veldora's older sister. So this is one reunion that would be most interesting. She mentions how Veldora is weak, but like Clayman this is not the case. We know Veldora is basically surpassing his aura/strength at the moment.
What is more interesting is Leon's theory is in fact spot on. While Rimuru's goal is to go after him, it is worth pointing out Leon will a tough one to go against in the future. He's clearly a man of both wits and strength unlike Clayman which the series has pointed out compared to the other Demon Lords he is weak.
Even more suggesting that Rimuru being capable of doing this would in fact rival Guy and Milim. We know Rimuru got a lot stronger, but being able to match up to Milim is remarkable considering the difference when those 2 first interacted.
As you would recall at the end of S1 Rimuru saved Shizue's students. We learn this directly interferes with Leon's plans. It seemed by saving them Rimuru killed the experiments that Leon was going after. Perhaps he was waiting for the students to die before conducting the experiment again? And the students who are now saved and under protection basically make it impossible to conduct the experiments? Or perhaps there is a 3rd party interfering.
One thing is for sure, Rimuru is putting his name out there and getting both Leon and Guy's attention. The question is it the type of attention Rimuru wants from these powerful figures? Granted he does want to go after Leon and get answers at him at some point so he can fulfill Shizue's wish.