yup he pretty much is.all he does is draw cards. the only thing that could kill you is if he uses exchange of the spirit and then forces u to draw cards with monster cards like cyber jar and morphing jar. he actually beat me once with that combo, but only cuz i let him live and i got overconfident. and luckily he's and obelisk blue so u get easy DP.
No,the most useless duelist is Fat Dorothy Girl.Just beat her today and she don't even know how to summon.On the contrary,Sadie is 10 times better than dorothy,she have 250 duelist bonus,maybe the highest one