POW's omicron is specifically for making Conquest easier, including buff/debuff feats. Those effects trigger when POW's team uses specials. POW has an AOE. Now, think about this: if the feat disk in fact left the enemy leader vulnerable to normal damage, POW would kill it and render the effect of the disk pointless. What would be the point of creating this disk if it had anti-synergy with POW's Conquest omicron? The leader is supposed to only be vulnerable to instakills, so you can bring in a team without instakills, hit auto, and let the battle time out as your team farms buffs and debuffs.
That said, I think the disk is funny. Players who know what they're doing don't need it. It's a tool for people who can't be bothered to figure out how to complete feats without a cheat code, but they, as it turns out, can't read.
I have no idea why OP is complaining. This is the easiest Conquest that I remember. I wasted a bunch of energy on stupid experiments and still hit the red box in 4 days. Didn't use the feat disk because by the time I unlocked it, I was nearly done with status effect feats. You've got some counterfeit cents there, OP.