Doing quests, I've reached the alchemy quest. And, well, one of items I need is greatwood. I just unlocked the greatwood research and...I'm scared considering the recipe and what I need to do. Heck, I don't really know what to do. I unlocked the runic matrix, I'm guessing it's related to that. (If I figure this out, I should be able to get runic armor as a bonus)
It's an infusion recipe. The Runic Matrix is one component of the multiblock structure you need for infusion crafting. Google a tutorial on infusion crafting to find out how it works.
This particular recipe requires a lot of essentia. Just make sure it's all in jars near the infusion table. The range seems to be quite far, but keep them within ~8 blocks so they're definitely in range. Have maybe 10% extra of each essentia type in case of complications - if the infusion crafting stalls waiting for essentia or items, it will slowly destroy essentia inside it, and then it will need more from the jars.
Surround the pedestal with stabilizing items in a symmetrical pattern - each stabilizing item should have another one of the same type horizontally opposite from the central pedestal. If you have a water crystal cluster 2 blocks east, 1 block north and 3 blocks down from the central pedestal, you should have another one 2 blocks west, 1 block south and 3 blocks down. I found that water shards are the easiest to automate, so every empty space in my infusion crafting area has a water crystal cluster. Crystal clusters, skulls, nodes and candles are valid stabilizing items. You should already know this part from the tutorial you found. Technically you don't need any stabilizers, but they reduce the chance of random bad things happening, especially since this recipe has "dangerous" level instability (IIRC).
When you have everything set up (make sure to have a few extra of each ingredient in your inventory, but you should know that too) start the infusion process by right-clicking with your wand. And then stand there and watch it - this recipe takes forever - and if any items get knocked off pedestals, or destroyed, put them back on. One of the random effects might cause you to take damage - that's not really a problem, as long as you're fed, so don't be alarmed.