Advent

When the Advent kills every electronic device on Earth, Drew Michalik is working inside a secret government facility in Washington, D.C. — which promptly becomes a dungeon. System screens and a handful of reality-altering Xatherite crystals are his only tools for getting out, and escaping is only the first step toward leading what's left of humanity.

Progression: slot-based spellcasting — Xatherite crystals socketed into a mana interface decide a caster's spells, so every build is assembled piece by piece.

Reader fit: you want a mage-focused system apocalypse that widens into settlement building and faction politics.

Texture: methodical, tactical, military-flavored.