First off, do not compare rasengans of Naruto Km/sage mode to minatos! He is wayyyyy out of minatos leaague when it comes to that jutsu!
He just have more variants. In terms of basics(normal rasengan), Minato's has shown to be greater and more powerful. Even KCM Naruto's rasengan barely phased Tobi when it hit him:
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When he lost more than just an arm to Minato's rasengan:
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Compare their size as well. Look how big Minato's normal rasengan is:
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Look how small KCM Naruto's rasengan is in comparison:
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On the above pic look also at the difference in damage it put on the ground, compared to this that leveled up the entire battlefield:
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Second; Do not compare any level of rasengan to a TBB! That is a fail!
I'm not comparing both, i'm comparing their caracteristics, something showed and said by the manga itself
Then you out right ignore the fact that obito jump and recovered asap from the attack! -_____-
I ignore nothing. I know he did that, like i know he also was so damaged(with a missin-arm) that he decided to flee away a second after. What happened later like you said we don't know, but if he fled, there was a reason behind it
Minato has no counter for hydra mode nor true form, Oru wins every single time! Oru knows minato and his secrets while Minato barely has anything on oru and even underestimates his talents. Oru is smarter no disputing, and has more outs then minato. And if the only argument any of you have is decap (when i proved with life and manga facts it will not work).
Oro has more knowledge, that's it. Minato is the smarter one(in battle). Oro's hydra technique is as featless as Prime Hiruzen, so we don't really know its great power or weakness. In appearance it has shown nothing that other summons couldn't do/doesn't have besides it's size
Obito never showed he healed from minato rasengan the moment he was hit, that is fanfiction with 0 manga proof. And Oru has take way worse things then a rasengan and has survived! Rasengan isnt killing him, and isnt killing allot of ninjas shown btw. Show basic rasengan feats not anything from naruto sm/km/bm using rasengan.
He obviously healed from it, otherwise he would have stayed with a missin-arm at the very least. He fled and there was a reason behind it. Not even mentioning the fact that judging by his size during that night, he may have been protected by Spiral Zetsu as well, unfortunately Kishi never really expanded on it