Odolwa destroys the Deku Palace by basically showing up. Link one-shots him in base. The swamp was poisoned in the manga, too. Skull Kid with the Majora's Mask cursed the whole world, causing problems everywhere, and he was the one who sealed away the Giants, poisoned the swamp, caused the eternal winter in Snowhead, and obviously heated up the water in Great Bay as well.
Link one-shots Goht as Darmani, Gyorg as Mikau, and
Twinmold seemingly in base, but the whole Ikana Canyon and Stone Tower segments are skipped, so Twinmold is practically featless.
The Moon wasn't called down by the Skull Kid, but rather was an expression of Majora's desires. The world within it was a spiritual plane of his. There's the world in what's essentially the prolog with the dragon and the traveller where time doesn't flow. The song the traveller was saying was causing wishes to bubble up as a whirlpool of desires and begin to come true within the dragon, which caused time to begin. Time was born. The song caused the whole world to crumble and it was tanked by the traveller and the armour of the dragon. Out of this armour, the traveller made the Majora's Mask, sealing the dragon's power within it.
So basically, to conclude:
> Odolwa is fodder, seems High 8-C with pretty good poison hax that affects the whole of that part of the world with his presence. That could be calced for a higher result, scales to base Link.
> Goht and Gyorg retain their feats, so are still High 6-C, scales to Darmani Link and Mikau Link. They curse the whole lands with their presences so their basic hax.
> Twinmold is nigh-featless, only got oneshotted by what seems to debate Link. The scan might denote some large size, though.
> The Majora's Mask caused all the curses, so they all scale to him, so he has the poison hax of Odolwa, the freezing hax of Goht, and the heating hax of Gyorg. I didn't post it above, I could find it if needed, but he also turned Kafei into a child. The Moon is an expression of Majora's desires and the worlds within the Moon are worlds of Majora's soul. Majora was made from armour that tanked the destruction of the world that came to be Termina, and also has the power of wishing, notably powerful enough to create even time. He can seal people, as he does the Giants. He's Low 2-C, and this scales to Oni Link.
> Kafei is actually considered surprisingly powerful to base Link.
> The Giants still held up the Moon, which could arguably be scaling to Majora, since the Moon was an expression of his desires. That's a very casual feat, though, and the Moon only stopped because the Skull Kid forgave the Giants.
> The tiering for Link was gone over above, but the hax are going to be gone over here. He shows the ability with his Ocarina to go back in time, which resets events and memories, and he can reset his biology by turning the altercations into a mask via a song. He can become people who are dead or are dying by music and can turn them into masks and sooth their souls. As Mikau Link, he can create a field of electricity around him, and he can summon the Giants with music. He can interact just fine as Oni Link with Majora within his own spiritual plane.
> There isn't much at all in this manga for speed for lower tiers, there is only the feat of moving before time existed for the dragon and the traveller and Majora, which also scales to Oni Link.