Hey Alfonzo, welcome!
I have considered
Saltblast, but 5-mana is just so much, and it doesn't even buy you instant speed! I was in fact more tempted by
Mass Calcify, to kind of push the white-matters theme, but the mana costs are just too high!
Vile Requiem seems very cool (sweet flavour), but horrifically slow, even with proliferate. Maybe I will come back to looking at it if I add a heavier Enchantment focus.
Wild Mongrel is a consideration, but only having a single colour, even if it is variable, is less important than having lots of colours as it turns out.
Chris, I can understand your concern.
Increasing Savagery + Double Strike is pretty terrifying. What actually excites me more is
Increasing Savagery +
Fathom Mage, but that is because I have this tendency to play decks for which the opponent's life total is usually just something to worry about later. I think
Increasing Savagery could be stepped back, maybe to something like
Common Bond or
Give / Take. Actually,
Give / Take seems really sweet, especially in my '+
Fathom Mage' scenario. Draw all of the cards!
Jason, I think you are right in regards to it being unlikely that
Homicidal Seclusion will pump a Double Striker. I didn't see the card in that light, and thought of it more in terms of incidental support for that theme. I saw it as more of a control-oriented card, but I am not really sure that it has a place.
Aside, on Exalted.
Cathedral of War in the Utility Land pile (for a more conventional cube, not this one)? It doesn't really tie back into any typical themes, but I could see it being taken.