This article discusses how to obtain a large number of Nether Stars by using items and mechanics from multiple mods.
Withering Source
Using a weapon with the Capture enchantment to kill a Wither has a chance to obtain a Wither spawn egg.
Spawner source
You can move the spawner in the structure using the Shear Helper, or you can go to the Wither Skeleton riding a Phantom next to the Sky Knights battleship to farm (its head has an empty spawner).
Place the spawner, then place the Life Implanter from Plant Magic on top, place the World Accelerator next to the spawner, and use a screwdriver to switch to solid block mode.
That's it for the spawning part, below is the execution.
Hold this item and stand where you want the wither to gather, then shift+right-click
For example, the place where my crosshair is pointing is where the Wither will be executed later (when the Wither takes damage, it will destroy surrounding blocks. Using the slaughterhouse has a chance to crash the server, don't ask me how I know. Reinforced deepslate won't be destroyed by the Wither, but mining by hand won't drop it. You can use the Shearing Helper to place it, the source is on the frame in the middle of the ancient city).
Put a rail inside, use a dispenser to place the minecart, it is recommended to have 23,
Build a 5x5 platform centered two blocks away, then add two blocks along the edge, and cap it as shown.
The device to kill the Wither is ready. Use something that can absorb drops, such as a magnet-upgraded backpack.
Below is to put the Wither into the cage
Use magic source stones to enclose the spawning area, with the border 5-6 blocks away from the spawner, and one block higher than the spawner's position.
Place the magic source jar on the magic primordial stone, throw the scroll in front into the frame, and a portal with death positions everywhere will be formed.
Finally, block the light and put the wither spawn egg into the spawner, then you can automatically spawn withers.
Attach a picture of the completed work. If multiple world accelerators are applied, it may be too late to kill them, causing too many withers to be squeezed out. You can also completely wrap the bottom.
Note: The wither spawner should be placed in the overworld. The void and superflat will not spawn mobs without NBT, and the spawner cannot spawn the wither.
Claiming land can prevent the explosion of the wither's head, but it cannot prevent the destruction of blocks when the wither is damaged.
It is recommended not to place the machine at the base, otherwise it will be very noisy and the Wither health bar will occupy the screen.