This is not the best or only way to win. This method requires multiple expensive upgrades, and may not be possible depending on the RNG. That said, if the stars align, this is arguably the most sustainable build.
1 Non-arcane source of damage (any 1sp cantrip EXCEPT Magic Missile will do.) 1 Arcane Translocation spell (Dispersion is the cheapest at 2sp unless you find a circle).
Arcane Skill (level 5): Arcane Accounting. After casting the last charge of an arcane spell, refund one charge of all non-arcane spells.
Nature Translocation Skill (level 5): Silkshifter. Produce webs adjacent to the Rift Wizard. Casting a translocation spell on a web destroys the web and recharges the translocation spell.
If you find Arcane and Nature circles 1 rift apart from eachother, that's a minimum cost of 8 for the skills and 2 for the spells. It is theoretically possible to get this running by Rift 3 if you're EXTREMELY lucky. (1 starting orb, 3 orbs per each of 3 rifts = 10 orbs).
Stand in an open area. Spam Dispersion until only one charge remains. Every time you want to recharge your non-arcane spells, start casting Dispersion on webs.
Works best with powerful spells that have limited charges, such as Word spells and Dragon Conjurations.
Here are the downsides of this build:
If you DON'T find the right circles, the startup cost is 1+2+5+5=13. That's more than FOUR rifts worth of orbs. Having infinite spell charges won't help you if you don't have enough SP to buy good spells in the first place.
Does not recharge Arcane spells, which are some of the most powerful available. Mystic Power, Mystic Vision, Death Cleave, Dominate - you'll still need to drink potions to use these spells.
Every time you drink a mana potion, all of your translocation spells will be fully charged. In the case of Dispersion, that means you need to spend 14 turns casting it at empty ground before you can start casting it on webs again. The more expensive Teleport only has one charge by default, but when upgraded it still has three charges - so you would still need to cast it twice before you can use it on webs.
Webs are very unreliable. If they generate over a chasm, you can't directly teleport onto them with Blink or Teleport (though Dispersion still works). You can't predict which tile will grow a web next. Enemies - and FRIENDLY MINIONS - will destroy webs by walking onto them, stunning themselves in the process.
Casting a translocation spell every other turn to recharge your main spell is TERRIBLE action economy. You're basically giving gates, summoners, buffers, and debuffers twice as many turns. Trying to recharge spells during combat is often unwise (unless you have mapwide CC from Word spells, lol).
Lastly, experienced players don't need infinite spell charges. There are plenty of mana potions lying around as long as you have the spells and experience needed to clear rifts efficiently.
Other spells and skills of note:
Arcane Spell: Devour Mind (level 3). Living targets only, deal 25 Arcane damage, then if the target health is <50% deal 25 dark damage.
Gluttony upgrade (1 sp). If Devour Mind kills a living target, refund one charge.
This is an arcane spell that can be infinitely cast on it's last charge to trigger Arcane Accounting, without bothering with webs from Silkshifter. Unfortunately, it has some huge downsides. It kills most enemies in one hit, so it's shocking difficult to run out of charges on purpose. It only targets living units. Very short range. About the only thing it has going for it is that it ignores Line Of Sight. You can't cast it on friendly summons, only enemies.
I wouldn't depend on Devour Mind for this build unless you find a good shrine that increase's it's range. That said, it does great damage and is still a decent damage spell.
Nature Conjuration Spell: Ringe of Spiders (level 5). Summons a ring of spiders surrounding a target, which are in turn surrounded by webs.
You still need Silkshifter to refund translocation spells that target webs, but this spell makes it easier to generate lots of webs for you to target.
Arcane Skill: Arcane Shield (level 4). If you don't have a shield and cast an Arcane spell (including arcane translocation spells) gain 1 shield.
Helpful for staying alive while recharging your spells.
Arcane Nature Skill: Thorn Garden (level 5). When you cast a Nature or Arcane spell, summon two Fae Thorns near the target.
Generates free minions for enemies to target whenever you recharge your Arcane magic. Be warned that this may interfere with your pathfinding.