As a matter of fact, the trigger goes off only after Duplicant has actually entered the battlefield
If you hover over the search bar youll see a pop-up showing you all the various terms you can use to narrow your search
While not explicitly being considered a Stax card, it is usually a welcome addition to a Stax style deck
I generally prefer Clones since you can recur them, bounce them, or flicker them for another go
Possibly better, if you have ways of making tokens during your opponents turns
Card Set(s) -TWO LEGENDS- [OP-08] CARD VIEW OP08-003 | C | CHARACTER Twenty Doctors Attribute Wisdom Block icon 2 Effect [Blocker] (After your opponent declares an attack, you may rest this card to make it the new target of the attack.) Card Set(s) -TWO LEGENDS- [OP-08] CARD VIEW OP08-004 | C | CHARACTER Kuromarimo Attribute Strike Block icon 2 Effect [On Play] If you have [Chess], K type Character card with 4000 power or less rested