Arch Blooms are large ogre like floral monsters that are able to revive themselves after death. They appear like massive green humanoids made of thorns and vines with a large blooming flower for a head. Arch Blooms are inexorably connected to another flower called a Throne Blossom. As long as an Arch Bloom's Throne Blossom remains, they are able to continuously regenerate, no matter how much damage they take. This connection earned them the nickname of "Floral Liches." Arch Blooms will typically plant their Throne Blossoms in a dark and secluded place they can easily protect and will violently kill anyone who intrudes on their territory.
And Arch Bloom was notably encountered by members of The Tempest Brothers Expeditionary Company where it had laired in an abandoned mine in Wyvern's Roost.