[WIP] Add RTP monster

[liam-middlebrook]

I'd appreciate some feedback on balancing out the effects of killing an RTP.

[liam-middlebrook]

I'll amend the commit (hopefully) soon to include my testing methods.

I'll also likely change around how the random selection of consequences happens. I'm hesitant to make each individual consequence a separate rng call, because I don't want to risk things getting called extremely rarely because of how the rng-engine works. So I'd appreciate if you have any thoughts on the matter. I was thinking having 2 or 3 rng values and then doing calculations from those on whether or not a consequence would be activates.