It still carried the power to destroy mountains with ease as you can clearly see it slice through several kilometers of land before impacting the two mountains, he's clearly above mountain busting from that showing.
@aka_tsuki: it cut the top of the mountains off, not the entire mountain
he didnt react to naruto, naruto ran into him, he wasnt even able to phase first(wait thats obito) madara reacted fast enough because naruto wasnt going that fast, he was making a mini bijuu bomb which takes a bit of time
the six paths arent that strong. sure they can create bijuu bombs, but that can be deflected with haki to a safe distance. hell based on what we saw of naruto, WB could deflect it with his hand and throw it away before it explodes. as i said before, BB can absorb the bijuu bombs and send them back if he wanted to, and if they do an even bigger one, then they are totally screwed. but anyway, this fight is between the two listed above
The 6 paths could spam their bijuu bombs and even combine them together to make one big enough to send an entire forest and fields of mountains to waste... From showings of Naruto finghting all 8 of the Jinchuurikis they were destroying rivers and mountains from crossfires.
And how the heck is WB and BB going to put down an edo Madara? The OP has no restrictions which should mean this is Madara at his prime (Edo Form). And Madara doesn't need Kabuto period, he's already shown the ability to break out of Edo Tensei so Kabuto is a non-factor here. For the most part, Madara can spam his meteorites or mokuton clones if he's just blood lusted.