It should work exactly as my accessory, First To Victory, which gives 25% EX Force, and it does work for all three stages ;)
I always hated CoD, it's the character i always have the most difficulty against in the entire game, because she's so damn unpredictable, the problem is that when she's at level 150, she begins with 5000 BRV and her magical attacks take almost 1000 BRV, so if i get hit even one time, i'm pratically screwed ._.
Oh and to top it off, i was fighting on Pandaemonium...Goddman Stage xD
Current PC Build
CPU - i7 8700K 3.7 GHz (4.7 GHz turbo) 6 cores OC'd to 5.2 GHz with Watercooling (Hydro Series H110i) | MB - Gigabyte Z370 HD3P ATX | Gigabyte GTX 1080ti Gaming OC BLACK 11G (1657 MHz Boost Core / 11010 MHz Memory) | RAM - Corsair DIMM 32GB DDR4, 2400 MHz | PSU - Corsair CX650M (80+ Bronze) 650W | Audio - Asus Essence STX II 7.1 | Monitor - Samsung U28E590D 4K UHD, Freesync, 1 ms, 60 Hz, 28"