venser

[Magician]

If a venser is in play and my opponent vials in another one, will he get to bounce my creature?

[Metaknight]

the vialed in venser will have the ability to bounce a spell or permanent, but will die right away.

[TrialByFire]

The long answer: Venser will come into play, its ability will be put on the stack, and then the active player would get priority, so state based effects are checked and both Vensers die. Then the active player will get priority. If both players then pass, the ability from the second Venser will resolve.

[Anusien]

The long answer: Venser will come into play, its ability will be put on the stack, and then the active player would get priority, so state based effects are checked and both Vensers die. Then the active player will get priority. If both players then pass, the ability from the second Venser will resolve.
Almost.
Venser, Shaper Savant comes into play and its ability will trigger. The game will check State-Based Effects, and both Vensers will be put into the graveyard due to the Legend Rule. Then Venser's ability will target and be put onto the stack. Then active player gets priority.