Unfortunately, this move doesn't work, either. There are two reasons for this. The first is that in the example you stated, since the trigger for Dodrio being able to use Drill Peck was the turn ending, by the time Dodrio attempts to use Drill Peck, the turn would have already ended. The second is that there is no guarantee for Dualize to work on the target; if the move fails, then there is no opportunity for the player to enter a move in between the turn.
Originally Posted by cascadethewarrior
While the second case can be changed by making the user be able to enter a move, unlike with Baton Pass and Explosion, where sending out a Pokémon is the last thing in the resolution of the move, it isn't with Dualize, since the effect of Dualize doesn't actually end until the second move is used.
The bad thing is that the following scenario doesn't work, either:
Turn 1: Dodrio used Dualize on itself. Swalot used Sludge. (Turn Ends.)
Turn 2: Dodrio used Drill Peck. Dodrio used Agility. Swalot used whatever. (Turn Ends.)
This is because the prompt for the turn to begin (or the prompt to wait for the other person to finish making choices) triggers after selecting something that ends the user input time frame. In other words, there is no opportunity for the second move to be chosen.
In any case,
New Item: Harness Unit
"A harness worn for adventuring. Prevents the holding Pokémon from landing critical hits, but boosts the power of its moves."
- Prevents the holder from landing critical hits. In return, each of the Pokémon's moves has its power increased by 20%.