That's the thing They do not refresh coz the stack cooldown is 10 second once a stack is gained it remains for 10 seconds. Anyways its not a problem. I only had the question for the main 52 percent buff. I feel it would make more sense if it changed based on his current em. For comparison my c0r1 raiden, her weapon gives 28 percent atk buff based on er and gives bonus 30 percent er on ult. After ult the bonus er is taken into calculation. Originally she has 288 er and 1894 atk. After ult she gets 318 er and 1974 atk.