Following on from this conversation, what happens if we replace Icthyomorphosis with Imprisoned in the Moon in that scenario?
I think:
- All Lands become all basic land types
- Dryad of the Ilysian Grove becomes a land and loses all other types.
- Dryad gains all basic land types to its own ability, then loses them again from Imprisoned in the Moon, due to timestamp order.
- Layer 6 removes all abilities from Dryad, including any mana abilities it may have inherited from becoming all basic land types (although, as it had already resolved as non-basic in layer 4, I'm not sure that's even relevant, as it wouldn't have received those mana abilities until layer 6 anyway), and adds "t: add colourless"