The Svarga

An ether realm would be an interesting addition to vanilla. Create a portal using blocks from all the unique or difficult places like frog lights, blocks of netherite, prismarine bricks or some sea lanterns, an end crystal, something from the deep dark and make it out of a combination of these things.

The realm would always be a foggy day. Have ethereal trees, shimmering blocks similar to glass but affected by the environment in a cloud like biome where parts of the ground work like powdered snow, unique flowers that give off light or debuff weightlessness and cause you to float/drift. Animals might include a spin on the cloud leopard or flying fish. Monsters/threats could be from plants that cause blindness, or demigods/ like piglins, but half god half human. Mini bosses could be disciple angels that drop 'addition pieces', items that can be forged into your gear like smithing templates, such as flight feathers into boots that allow you to hover for a period as long as you have elytra equipped. The final boss could be an eight-winged angel, and the prize an immortal egg that births a phoenix, which is initially attached to the player who slays the boss, but when it gets reborn, it has an opening to be claimed by someone else.