Talk:Excalibur/@comment-1.9.107.114-20151217054859/@comment-98.156.57.25-20151219182649

Did you change power duration at all? EB energy cost is based on both duration and efficiency, so if you tank your duration you'll see energy costs increase even if you have "max efficiency". This blog post has a handy graph that shows energy cost values for sustained abilities depending on your efficiency and duration: http://warframe.wikia.com/wiki/User_blog:Fegazeus/17.5_Duration_mods_and_drain