New miniclass idea I had, originally posted over at G+ but I figured I could share it here, too.
CHAOS MAGE
When you gain a level, if you have experimented with wild and uncontrolled magic, you may take the following move:
Wild Magic: Add " The spell manifests unusually, or has strange side effects, while still fulfilling its basic intent" to the 7-9 options on Cast A Spell. These side effects are not necessarily cosmetic.
Once you have taken Wild Magic, the following moves count as class moves for you.
Unstable Magic: When preparing spells, you may prepare any number of spells you wish as if they were one level lower. Level one spells prepared in this fashion are counted as half a level each. When you cast any spell prepared thusly, on a 10+, choose one from the 7-9 list, and on a 7-9, choose two options instead of one.
Greater Unstable Magic: When you cast a spell prepared with Unstable Magic, and roll a 6-, you succeed regardless, but choose three options from the 7-9 list, and choose one of the options, except "the spell is forgotten" to have a very pronounced effect. (The spell attracts a lot of unwelcome attention, the spell disturbs reality greatly for a -2 penalty instead of -1, the spell manifests extremely unusually with serious side effects, etc)
Warpwright: You are practiced at using the Ritual ability to give a willing or restrained subject a random mutation. When doing so, you can ignore one of the conditions the DM selects for the Ritual's completion. (The Metamorphica, by Johnstone Metzger, is an excellent free resource with hundreds of mutations arranged on one convenient table, should the DM not wish to make their own.)
Versatile Caster: You may attempt to cast a prepared spell as any lower level spell, including one not in your spellbook. To do so, roll +int, modified by any -1 ongoing to Cast A Spell you may have. On a 10+, you succeed in shifting the pattern, and may cast it normally. On a 7-9 you succeed, but cast the new spell as Unstable even if the original wasn't (and if the original was, choose an additional 7-9 result from Cast A Spell on top of the extra Unstable Magic normally gives you).
Discharge Flux: You may discharge all accrued -1 ongoings to Cast A Spell caused by 7-9s from that move. The DM will tell you what the flux appears to be about to do, some harmful (or at least unusual) effect: you may opt to "ground" the flux and take 1d6 armor-ignoring damage per -1 ongoing you had rather than let this effect come to pass.