The only costumes I've seen at Sakuracon have been one or two Seras's, a handful of Alucard and a few Integra's and Shroedingers, and at SC2011, I didn't see any Hellsing characters but one Alucard =/ I'm hoping next year since I'll be going as
Seras that there will be a few more out there.
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In War, Victory.
In Peace, Vigilance.
In Death, Sacrifice.
They Will See... We'll Fight Until Eternity...
Come With Me, We'll Stand And Fight...
Together.
Through Our Strength We'll Make A Better Day Tomorrow...
We Shall Never Surrender.
Sakuracon '12~ Victoria Seras (Blood Version)= Hellsing