Obtaining Realmstones

Precasia Realmstone:
    Dropped from Bush Baby, Stinger and Terradon.

Abyss Realmstone:
    Dropped from Anemia, Bloodmist, Trickster, Slimer and Linger.

Haven Realmstone:
    Dropped from Magicke, Goalby and Voliant.

Mysterium Realmstone:
    Dropped from Bugeye and Fungung.

Deeplands Realmstone:
    Dropped from Clown, Ghost, Faceless Runner, Shade, Trickster and Doubler.

Celeve Realmstone:
    Dropped from Clown and Jumbo.

Gardencia Realmstone:
    Dropped from Giant Slug, Dyrehorn and Sunny.

Immortalis Realmstone:
    Dropped from Death Hunter.

Creeponia Realmstone:
    Dropped from Host and King Creeper.

Iromine Realmstone:
    Dropped from Dweller and Mechachron. Also drops as Foraging loot at level 55.

L'Borean Realmstone:
    Dropped from Treasure Box, Corallus and Neptuno.

Vox Ponds Realmstone:
    Dropped from Flower Face, Squasher, Exoid and Pod Plant.

Barathos Realmstone:
    Dropped from Bouncer, Eilosapien and Paladin.

Dustopia Realmstone:
    Dropped from Hunter, Grillface, Shifter and Stalker Prime.

Lelyetia Realmstone:
    Dropped from Grobbler, Seeker and Surveyor.

Ancient Cavern Realmstone:
    Dropped from Automaton, Flower Face, Bloodsucker and Rock Critter.

Crystevia Realmstone:
    Dropped from Case Construct and Construct of Mind.

Candyland Realmstone:
    Dropped from Chocko, Sticky, Koko and Cherry Blaster.

Shyrelands Realmstone:
    Dropped from Lost Soul and Stimulosus.


Teleportation to Greckon, Runandor and Lunalus

Greckon and Runandor portals can be found in the Mysterium dimension on the Portal Tower structure. 
You also need to buy Realm Travel Ticket from the Portal Master, which stands near the portals.

Killing Terrestrial in the Overworld will create a portal structure that leads to Lunalus. 
Terrestrial is a very rare mob that spawns during Full Moon Event in the Overworld.
