To be honest, I was a bit unsure of what to do there. The flavor of the move in the Data Audit Thread says that the user casts "a shadowy beam"; personally, I believe that this could be used in order to avoid attacks just because of the way it was phrased in the Data thread. However, if this somehow violates a ref's creative license, I suppose there's nothing I can do. However, I'd like to argue for the use of certain moves as dodging moves, for both practical and flavor reasons.
Regardless, I suppose I should change it if you don't like it. Waterfall and Hydro Pump will KO Gastly, and Dratini will target Monohm instead of Tirtouga, killing it. Also, I thought it was 2/3rds and not 3/4ths, but I'm probably wrong.