This is the second time I've found this structure in my custom modpack. The blocks do not show up on WAILA, nor can I find them in JEI. I looked at the blacklists for both mods and nothing was there. I'm using a very large number of mods, so I cannot simply narrow it down based on looks. I'm very baffled and kind of creeped out, it'd be a huge help if someone could tell me what mod this is from and what it's purpose is.
Actually Additions Actually Baubles Akashic Tome Angel Ring To Bauble AppleSkin Aroma1997Core Aroma1997s Dimensional World Astrak Sorcery AutoRegLib Backpacks! Base Metals Baubles Better Builder's Wands BetterFps Bibliocraft Bibliotheca Biomes O' Plenty Bookshelf Ceramics Chameleon Chisel Chisel & Bits Client Tweaks CodeChicken Lib 1.8+ Colossal Chests Common Capabilities Compact Machines ConnectedTexturesMod Controlling Cooking for Blockheads Cosmetic Armor Reworked Crafting Tweaks CraftTweaker Cucumber Library Cyclic Cyclops Core Dark Utilities DecoCraft2 Diet Hoppers Ding Ender Storage 1.8+ EnderTanks Engineers Workshop Extra Utilities Farming for Blockheads Fast Leaf Decay Fullscreen Windowed (Borderless) for Minecraft GooglyEyes Hopper Ducts Hwyla iChunUtil Immersive Engineering ImmersiveEngineering-0.12-80-core Integrated Dynamics Integrated Tunnels Inventory Tweaks Iron Backpacks Iron Chests Item Scroller JEI Integration JourneyMap Just Enough HarvestCraft (JEHC) Just Enough Items (JEI) Just Enough Resources (JER) KleeSlabs Light Level Overlay Reloaded MalisisCore MalisisDoors Mantle MMD OreSpawn MmmMmmMmmMmm Mob Grinding Utils Mod Name Tooltip ModTweaker Morph Morph-o-Tool Mouse Tweaks MrCrayfish's Furniture Mod MTLib MultiBeds MultiStorage Mystical Agradditions Mystical Agriculture Natura Nature's Compass Neat Nether Metals NetherPortalFix OpenBlocks OpenModsLib OptiFine_1.12.2_HD_U_D1 p455w0rd's Library Pam's HarvestCraft Platforms ProjectE PTRLib Quark Random Things Ranged Pumps Reborn Core Reborn Storage Redstone Flux Redstone Paste Refined Storage Refined Storage Addons Reliquary v1.3 ShetiPhianCore stimmedcow : NoMoreRecipeConflict Storage Drawers Storage Drawers Extras The Twilight Forest Tinker I/O Tinkers Construct Tinkers' Addons Tinkers' Complement Tinkers' Tool Leveling Tiny Progressions UniDict VeinMiner Waila Harvestability WanionLib Wawla - What Are We Looking At Wolf Armor and Storage
If you're in 1.10 or more, you normally have a modlist.json file in your mod folder. If you're not, make some screenshots, it will be easier.
I didn't saw your manually edit. So, it should be Astral Sorcery or Reliquary. If it's not, idk. But if you want to permanently remove this structure, you'll have to remove the mod which adds it and you'll have to move, because chunks stay as they are.