Gavin "Tweek" Dempsey
... that professional Smash Bros. player Gavin "Tweek" Dempsey was considered the best Bowser Jr. player in the world, but started winning tournaments only after switching to other characters?
... that <a href="./Super_Smash_Bros._in_esports" id="mwBnA" rel="mw:WikiLink" title="Super Smash Bros. in esports">professional <i id="mwBnE">Smash Bros.</i></a> player <b id="mwBnI"><a class="mw-redirect" href="./Gavin_Dempsey" id="mwBnM" rel="mw:WikiLink" title="Gavin Dempsey">Gavin "Tweek" Dempsey</a></b> was considered the best <a class="mw-redirect" href="./Bowser_Jr." id="mwBnQ" rel="mw:WikiLink" title="Bowser Jr.">Bowser Jr.</a> player in the world, but started winning tournaments only after switching to other characters?