This idea is very simple: There are invisible portals in your world, they are generated in created chunks and lead in generated chunks (inclued other dimensions). Sometimes they disappear, move or appear. Portals don't drop upgrades!
They can have upgrades:
Block update: The portal is a block, so it can break with the correct tool (I'll talk about later)
View update: You can see where the portal lead
Place upgrade: The portal start swapping blocks between where it leads and where it is (If he's in a cave grass will go in the cave and stone/ores/etc will go at the other portal
Dimension upgrade: The portal can lead to another dimension
Color upgrade: You can see the portal, he's colored!
Entity upgrade: The portal become an entity! He's neutral and sapient (if you're holding an antiportal item you shouldn't go near him...)
Eat upgrade: Sucks everything inside it. EVERYTHING will be destroyed. Comes with the destroy upgrade.
Destroy upgrade: Everything/everyone that gets inside will be destroyed (stuff, life, entities, xp, items, blocks, energy, etc...)
Portals fragments: Dropped by portals when you destroy/kill one
Anti-portal fragment: Only found in portal dungeons
The portaler glasses: These glasses are crafted with portal fragments and let you see the portals
The Unportailer: The only tool known to destroy the portals in less than 5 seconds, and to kill the Portals in 2 shots (only works on portals)! Crafted with anti-portal shards.
Portal dungeon: No doors, there are portals. It's a big dungeon with more than 1 chest, 1 room, 1 mobspawner. Has his own dimension. Generated with unbreakable blocks (not bedrock). Portals has more chances to get upgrades here. Don't lose the door which lead here, or you'll never be back home... Has a boss: The mega portal.
Living portal: Can trade very good items with you, if he doesn't hate you.
The mega portal: You must kill him, he may be back (find why). If you get out the portal dungeon without defeating him after he spawned, he'll destroy your world! He'll follow you! You must kill him! If you kills him your world is safe.
PM me if you create this mod! Or just say it in this thread.
The entire thread is in the spoiler (if you need it for anything). This thread is now abandonned.