It seems depending on the Health of the opponent along with there meter, The overdrive drain changes, A orochi, Rapid, Backstep, 2D 6D 236D gives 100 heat when the opponent has full health with 100 heat, 89 heat when the opponent has no meter with full health, 95 heat if the opponent has 40% health and no meter, And 100 heat if the opponent has 40% and 100 heat, See?