well i can beat the event with D´arc in the 20 Ap stage with 4-9 snatch stack on boss and got the gold chest like 90% of time
but can´t use her in 30 Ap stage so i barely can stack 1-4 snatch with ex skill on other hero in boss and i must say that the chance of drop gold chest is very low there, like 40% sure there more silver drop in these stage , i wish i could 9 stack on her e.e