Unless I'm misinterpreting Maro's definition, these all seem to fit the bill:
All of them need to be in an ecosystem full of dragons, dash, or facedown cards to be effective.
Deceiver is fine because morph has been used in several blocks and will likely be used again at some point down the line.
Warbringer's dash reduction is more of a bonus than anything. A 3/3 for 4 is in red's wheel house and it having dash itself makes it a fine card to run as your only dash creature in a deck. You either get a hasty 3/3 for cheap or you get multiple hasty 3/3s for cheap with the right draw.
Dragons appear in pretty much every set, so the dragon-specific stuff also isn't parasitic.
When I think parasitic, I think mechanics like splice onto arcane, which does nothing with cards from outside of Kamigawa block. In recent times, the gates-matter cards from RTR block are another good example of what I'd consider parasitic design (though they're on the lighter side of the spectrum).