ornn brings nothing to a fight? have you seen his ult?
the issue with ev right now is that nobody knows her. they dont know how she builds, her exact combos and timers or how long she can stay in a fight. ornn or kayn might not be ideal picks but they arent bad.
and ive played pleenty of ornn ranked, the best way to throw a game is to tilt your teamates by banning their shit. its not fun for anyone.
summary:
should you eve jungle yet? no
should you ban your teamates champs? no
should you play ornn/kayne/urgot ranked? sure, if you've got practice
also, who tf you calling "useless in a fight"? once laning phase is over riven offers jack shit while ornn will cc your entire team, give your teamates chances for more cc and maybe even knock them up twice. riven: will try to 1 v 5 and get more kills than her team, but will inevitably lose when her team falls off because she does shit in a teamfight.