Frenzied devastation has a 50% mana-cost penalty and twincast seems to use 2 counters, giving me the benefit of 2 counters in 1 cast. Does using twincast also double the penalty? or do I get to use 2 counters of frenzied-benefits for the mana-cost penalty of only one counter? Is twincast a mana-efficient use of frenzied devastation-counters?