The classic Pixelmon mod changes your Minecraft experience into a open world Pokemon game
With mods like Applied Energistics 2 and Immersive Engineering, offer a limited tech experience.
Biomes O Plenty, Climatic Biomes, and Underground Biomes all serve to spruce up the world and make exploring more fun.
There are many mods in the pack such as BiblioCraft, Mr. Crayfish's Furniture, and Chisel that make make building more interesting.
Finally, there are several mods dedicated to quality of life improvements such as, Inventory Tweaks, FastWorkbench, or Clump.
Over all, the modpack aims to provide the familiar Pixelmon experience with a couple twists to mix things up.