User blog comment:Simbey/Real Talk: Xerath rework/@comment-7481207-20140121171555/@comment-4012115-20140121193402

Old ultimate had half the CD of the new one and did massiv damage to all enemys hit within 1.3k range (+ old has 40%mpen)

New ultimate is (as said above) a long range finisher with high cd and decent damage vs multiple enemys but good damage vs isolted