General Premodern

This is a great idea. I’m not interested in building constructed decks but I bet it would be a lot of fun to play limited where every card is curated for the format.
I wonder how well it would translate to make the cardpool and then assign rarities for limited. A great task for employed coast-based magic casters...
 
Ramp in white feels just completely wrong to me. Like lifegain in red.
You can justify pretty much anything with flavour if you try hard enough.

White counterspells are just an example of white saying, "no, get back in line". Taxing effects like Mana Tithe are just that - a tax. Lapse of Certainty effects are bureaucracy. A hypothetical white Cancel would be an Azorius enforcer laying down the law.

White ramp, we actually have some examples of this in recent times, such as Deep Gnome Terramancer. It enforces a sense of fairness, the equivalent of the teacher asking if you brought enough gum for the whole class. You got ramp? Shouldn't you be sharing that? Even pure white ramp like a hypothetical white Rampant Growth that fetches Plains could be society banding together for the greater good, or imperialistic conquest.

Red lifegain is invigoration; bloodlust, passion, fighting through pain. Normally this is represented with power/toughness boosts, but that's just for creatures; how about the red mage themselves? You can't keep me down! I'm just having Illusions of Grandeur, you say? Who cares what you think?!
 
Really though, I assume the only reason we didn't get a colorshift Delusions of Mediocrity into red at some point is because they didn't want to risk touching the Trix Stove again somehow. It feels red as hell to be like "haha yessss everything is going great I have ten life and cannot possibly die oh no"
 
I think the red version would be more like “until the end of turn/your next turn you don’t lose the game for having 0 or less life”. Captures the spirit of a berserker who keeps fighting despite their injuries.
 
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