Bloody Betrayal is the steal a creature card for the set that immediately also creates a Blood Token
These two have had a few other cards as well, and Sada's, especially, have been powerful, leading her to become one of the most iconic trainers of the era and making her cards desired by collectors
In this case, it was the latter, so all the illustrator did was follow the materials they were provided with
Flux can be a dead card, but when you run into a busted artifact deck this will punish them quite effectively, and Zur can dig it out whenever it's going to be relevant
Its only appropriate then that The Ooze cards allow you to create more of these tokens whenever a creature that has +1/+1 counters on it already leaves the battlefield, or allow you to tap the card to exile a card from a graveyard and create a token too