Sleek feathers would not be necessary because Blaziken is a flightless bird, which tend to be less sleek than flying ones. ( d3lp4xedbqa8a5.cloudfront.net/… and themysteriousworld.com/wp-cont… ) And yes, chickens and roosters can fly (not the best fliers, but they can still do it) Not to mention there are roosters more fluffy than Blaziken. Also Blaziken's entire design is supposed to be a humanoid bird, so giving them t-rex arms would be strange. You can see even in Blazikens more realistic official art that he still has very much humanoid arms. ( statici.behindthevoiceactors.c… ) I think whether or not he should be fluffy or sleek or have human or t-rex arms is about personal preference.