What do I do to become the deadliest person in the world?
In brief: You can't.
While a Martial Artist does learn combat
skills, the final objective of a Martial Art is not to become the
deadliest person alive.
The Martial Arts recognize there will always be someone who is bigger,
stronger, faster, has a bigger knife, a more powerful gun, a longer range
missile, and so on. The objective, then, is to become the best that you
can be, regardless of how good anyone else is.