Nothing else is needed for this card to be effective
The real fun of this card is if you can duplicate the ability with cards such as Naban, Dean of Iteration, Harmonic Prodigy, or Strionic Resonator (or, if you really want to get crazy, all three)
If Spell Queller leaves the battlefield before its "enters" ability resolves, its leaves-the-battlefield triggered ability triggers, resolves, and does nothing
Unlike standard cards, V-Unions are played by first discarding their components, then assembling them on your Bench, once per game
There are so many different formats to play as an MTG player, but none are quite like Draft