And then there is blue
Ive played every one of these cards in Commander, and while only some of them see consistent play in my decks today, all of them can bring more out of your mana base in a white Commander deck
Both Scythe (with first effect, of course) and Immortality feel a little too strong: I would restrict one to once per turn and the other to twice per turn, depending on your thoughts over which should be nerfed more
Without Bridge from Below in the mix, theres a chance Dread Return isnt all that threatening, but a free reanimation spell for deck like Dredge is extremely powerful
If a creature's power is less than 0 when it's doubled, instead that creature gets -X/-0, where X is how much less than 0 its power is
Storm would dabble in Aria of Flame, the card Ensnaring Bridge and the entire deck Lantern Control existed