When duel is cast on a target that is already dueling, which ever instance of duel finishes first decides when the others finish.
The dota 2 wiki page is the only place i found that talks about this case and it says "Multiple instances of Duel on the same target work independently of each other, with each instance having its own duration". I assume this is no longer the case.
I have also tried this with Axe using lotus and Legion dueling him and then Rubick duels legion near the end and its the same outcome, except it is three duels in this case cuz of the lotus.
The duration works normally if Rubick uses duel on a separate target.
Also near the end (2nd last clip), you are seeing a Legion with aghanims dueling first, then a Rubick with no aghanims dueling near the same time. since duel with no aghanims has shorter duration, Rubick's duel manages to end Legions duel before Legion's finishes.
Ability name
Duel
Description
When duel is cast on a target that is already dueling, which ever instance of duel finishes first decides when the others finish.
The dota 2 wiki page is the only place i found that talks about this case and it says "Multiple instances of Duel on the same target work independently of each other, with each instance having its own duration". I assume this is no longer the case.
https://user-images.githubusercontent.com/120418933/207145239-395c8de0-7ed2-4166-8a90-104c37a7a3d4.mp4 (10mb file size limit, sorry for low quality video) reddit link below has higher quality video. https://www.reddit.com/r/DotA2/comments/zk7xs2/how_come_multiple_duels_share_the_same_duration/
I have also tried this with Axe using lotus and Legion dueling him and then Rubick duels legion near the end and its the same outcome, except it is three duels in this case cuz of the lotus.
The duration works normally if Rubick uses duel on a separate target.
Also near the end (2nd last clip), you are seeing a Legion with aghanims dueling first, then a Rubick with no aghanims dueling near the same time. since duel with no aghanims has shorter duration, Rubick's duel manages to end Legions duel before Legion's finishes.
Example Match ID (and possibly Timestamp)
6914240891 - 19:34