Have You Played... Master Of Magic?
I cannot believe nobody's done this. This isn't a nostalgia thing. I first played Master Of Magic in, I think, 2006, a solid decade after its 1994 release. I last played the magical strategy game a couple of years ago and honestly, it's still every bit as great.
You're a wizard, 'arry, either off the shelf or customised. Instead of statistics, you pick a number of spellbooks from 5 schools, or sacrifice some books for traits that offer specific bonuses - faster research, say, or stronger soldiers. Soldiers? Well, of course. You can't conquer both the known worlds without armies. But do you want to lead orcs, or lizardmen? What are the advantages of starting with beastmen, and how well would a town full of gnolls work with your 7 Death spellbooks?
Or you can just go with what sounds fun. It's basically all fun.
When you've made all your choices, you open with the standard 4X single town and scout unit. But your spell books and your choice of subjects has already drastically changed the game. A death mage will curse and poison rivals, summon evil spirits and claim their vanquished foes as undead lackeys. A nature dork will call upon spiders and bears, destroy enemy fortifications with earthquakes in the game's quick and easy turn-based tactical battles, and change the very terrain to suit their purpose. Perhaps you'll mix and match. Or maybe you won't focus on direct spellcasting, but use life spells to build your cities into utopias that pump out masses of advanced soldiers.
Maybe you started with humans but conquered a neutral city of halflings, whose innate farming bonuses open up bigger divisions of magic-immune paladins backed by devastating slinger barrages. What if you focus on building up hero units, clearing out dungeons and magic nodes for their powerful items, and turning them into unstoppable single-figure armies? What if you researched a spell called 'Armageddon'? You pretty much HAVE to cast that. I mean, come on.
I rarely finish any 4X campaign. I almost always finish Master Of Magic.