Rubies and Ruby Guardians

There are 5 Rubies per world and each one can be eaten or stored as a relic (which i discussed on my new inventory concept). Each one eaten or stored will permanently grant the player for that world with +1 inventory space. Each one is hidden and guarded anywhere in the world by a new mob called a Ruby Guardian. The Ruby Guardian will be something like a high jumping iron golem with more damage. Each ruby Guardian will spawn in with its own a unique structure (as in 5 new structures) ,making it easier to identify if you stumble upon it. Some may even require a bit of digging to find (see what I did there)