Mana charging works very differently on defense
Hawthorn is suddenly more relevant than ever: mana gain = counters mana cut; ailment reflect = she slows herself down; manashield = chance to resist mana cut if she fires before Hawthorn does
Poseidon is also a good counter even if the weak color, and could always use charge/magic/styx heroes to counter (Garnet + red stack comes to mind)