You should begin building tryndamere's ability's by selecting spinning slash, then mocking shout and as of level 3 select his bloodlust and max that 1st, at level 6 go for his ulti and after you maxed bloodlust begin maxing mocking shout because of the damage reduction it has on enemy and slow which gives you an opportunity to land a kill, you should level spinning slash last because its more of an aoe damage dealing ability, but it is pretty good to getting closer to your target or escaping from a fight so max it last.