For the future, most of these are fine. The specific elemental ones I don't like, and I'm glad they're gone. I'll give my opinions on the others just so you have some feedback when using the others, or making new ones.
Duality is kinda meh, and not that game-effecting since most teams run duo anyhow, but I'm fine with it.
Veil of X: are borderlines. I can see some cries of foul if this was sprung on someone by surprise when the team either didn't pick, or had already had discarded cards from those elements. Do all elements have a decent synergy with at least one of those elements?
Sacrificial alter is nice, but I'm not sure how many people would use it. Could turn into a "rich get richer" situation if played late in the game, since the teams in the lead could afford to make use of it more than the teams just hanging on. Good idea, but perhaps could use a tweak or two.
I like Gift.
Burst of color is interesting. Might favor the Underworld team though? Unsure. Might be hard to pull off the later in the war it appears, since teams may not have the cards to make a decent rainbow.
Elemental Victory is nice, I like it. Perfect as is.
Depletion Victory is good too. Perhaps favors
a tad? Probably not that big a deal.
Reinforcements: Good as is.