Methods of altering spell costs are deeply ingrained in the game, with examples ranging from Force of Will to mechanics like Affinity, Improvise, and Delve
It cant be blocked, targeted, dealt damage, or enchanted by anything they control
Commander damage can easily cause a loss without depleting a lifegain players whole life total, and building up a stack of life can often make you the biggest target at the table
Its a better rate than Divination within a turn cycle or less, and thats completely discounting the tax-inflciting side effects
If youve got another physical copy on hand to compare it with, thats perfect, but you can also use sites like Bulbapedia or LimitlessTCG to have a look at a pristine, digital copy
We've listed 100 cards in about an hour once we got into a rhythm