I think the concept of the team means that by definition our characters are all "aggressive".

Maybe instead of having be [i]beastial[/i] have Blood Walker be... more sinister? Instead of a monstrous demon he's more charming and deceitful, bloodthirsty but not animalistic... unless he's gone too long without blood, then maybe he could frenzy.. Think of classic Dracula and classic Lucifer, two very powerful creatures who can rip any mortal to shreds, but don't because they like to play with their food so to speak.

Maybe dial back the damage his claws and fangs do, let the sword be his main weapon. Make him more of a duelist perhaps. Let your character have superstrength, but let the Omega character be the tank. Molotov can be the fire guy, let your character do something else... like Telekinesis or the ability to Possess and/or the Mind Control those he's fed upon. And of course, the team could use another flier =P

Here's a [url=http://powerlisting.wikia.com/wiki/Demonic_Physiology]link[/url] that might give you more ideas.