This is on purpose IIRC, akeen to Shiv ult through Viscous cube unless Talon ult/Shiv ult does not take current buffs into account when being applied/used on another player.
Viscous cube protect from Shiv ult. Also I think Shiv ult should either net the target alive with Cheat Death on , or pass through Cheat Death but not putting it on cooldown.
This is on purpose IIRC, akeen to Shiv ult through Viscous cube unless Talon ult/Shiv ult does not take current buffs into account when being applied/used on another player.