Temporal chain states that other effects expire slower on an enemy by 40%. Impale states that it lasts for 5 hits.
If I impale an enemy with temporal chain, (5 hit)*(1.4 duration)= 7 hits, a whole number.
I just want to know if this is how it works.
A number of hits is not a measurement of time. "slower" thus does not apply to it.
Impale does have a duration (8 seconds) and temporal chains will make that duration expire slower. It also being removed after 5 hits does not interact with that in any way.