Set during the medieval period say between 500 to 600AD, there are magical creatures inhabiting the same world as us. These magical creatures actually exist in a parallel world but an impact from an unnamed asteroid created a disturbance that rippled through our world and theirs, tearing the fabric of reality asunder, and opened a gateway bridging both worlds permanently.
(Actually, this asteroid wasn't a coincidence, but the wrath of the last old god in the universe, named "The Terribly Old One"... nevermind, back to my question).
Very often, a few magical beasts would trespass into our world through the gateway and materialise; in this state they lose their ethereal body and become mortal. People soon discovered that they can consume and absorb the magical essence of a dying magical beast and soon it becomes a trend: Whoever absorbs the magical essence from the dying magical beast can experience a brief moment of guaranteed good luck. (Note that a beast's last breath contains its magical essence.)
Each person can absorb the magical essence from one dying magical beast in their entire lifetime. The magical power bestowed upon the lucky person will manifest once only, at some random time, and lasts a few seconds. Each magical beast can sustain tons of damage before dying. They are quick and agile but do not have ranged attack. (Bad news for those people who dare cross the gateway: The number of migrating beasts isn't a coincidence either, but that's not important.)
The question is: Since the chances of encountering these magical beasts is very slim, why are people encouraged to risk their life hunting them for sport? I'm pretty sure there is some kind of policing system in place to maintain peace and safeguard lives and property, but why isn't there any rule to keep people from courting death by participating in the deadly sport?