Minecraft – way to make mobs invulnerable in Minecraft Console Edition

The creeper spawn limit is 25 and the total hostile mob spawn limit seems to be 50. I tested this with in survival mode with a spawner that only spawns creepers, zombies, and skeletons. Different mobs may produce different results but I'm sure about the creepers. I don't feel like testing spawning parameters but it does seem to be the same as the wiki says. Hope this helped! This is after TU 14 btw

You have to build a nether reactor with a nether reactor with diamonds and gold. Then activate it. You will have to build it in a non used area. You have to be quick to collect the things you can get but you will get a few things.