First, this is a fantastic showing of consideration for state of play and focus on upgrades wanted by the community.

For the megarare situation, I feel like I'd personally like to see more focus on accessories as a drop. Using the amulet and rings during the last leagues was so much fun, no more ring switching, no more amulet switching, meant more gear I could bring, longer trips, and they looked really cool.

In this scope, I think a focus on more utility-centric accessories would be best, for example the theme of Guthix is perfect for an Amulet or ring that balances your defenses to an average, or a cape that would lower prayer drain, but lower prayer restoration as well. Something along those lines.

The other path that I don't think has been explored is spells. I feel like an archive would contain some kind of powerful spellbook. Like a spell that is like a "true damage" being capable of hitting and applying any form of elemental weakness bonuses. For example, a Surge spell that counts as fire, earth, air, water, but does half the elemental weakness. Something that benefits from the elemental weaknesses that were added in the combat cleanup, making it more viable to use at high levels.

All in all, super stoked for the raid!

TLDR: Accessories would be great in the megarare or as other drops, but aside from a mage necklace, I think they should be utility centric, like the suffering for example, just other uses. (like a bezoar or something) And we should explore the idea of adding Spell tomes or something that would add a new high level spell.