Raiden

As an esoteric lord Raiden is a great addition to most groups of mages, whilst having mid-tier attack and basic multipliers, his damage grows over time allowing him to compete surprisingly well. His real boon, however, is the reduction in ally skill cost, which is even more significant with the expensive ults of esoteric mages. Although not used often as a hero, his lord skill makes him a staple on the bench if you don't have a legendary equivalent.