It looks like the answer is "no". The effect is a temporary power granted to the target, which effectively means it terrorizes itself. It also applies only in PvE, so it would never apply to a player, meaning int would never have the opportunity to be in the presence of such global buffs (since NPCs don't use IOs!)
Blue
American Steele: 50 BS/Inv
Nightfall: 50 DDD
Sable Slayer: 50 DM/Rgn
Fortune's Shadow: 50 Dark/Psi
WinterStrike: 47 Ice/Dev
Quantum Well: 43 Inv/EM
Twilit Destiny: 43 MA/DA
Red
Shadowslip: 50 DDC
Final Rest: 50 MA/Rgn
Abyssal Frost: 50 Ice/Dark
Golden Ember: 50 SM/FA
Besides, there aren't any set bonuses which buff -tohit 
http://www.fimfiction.net/story/36641/My-Little-Exalt
Is the Demoralize effect on Assassin's Strike (-to hit and fear) affected by any set bonuses that globally boost fear or to hit debuffs?
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Mission Architect Handyman