Hey! This is another attempt at spellcasting, and perhaps will be easier to understand than the first that I released. This ones actually quite simple and I'll walk you through the design decisions for each level.

Spent a while making sure the Spell Tatoos motiffs are around the same usefulness. I made a table that rated each spell on the combat and out of combat utility, summed up the scores and tried to make it on par with shadow motiff using the 4 spells given by Way of the Shadow Monk. It is at level 6 as opposed to the lvl 3 shadow monk feature, and the spells they grant are usually quite situational or have bad action economy. Shadow sorcerer does not have any damage spells - and for good reason. Attacking would quickly be better than most damage spells as your attacks scale much better, so I've added the option to cast a bonus action. Flavorwise, casting by activating a tatoo seems faster - and this feels like more a sorcerer class anyway.

I've swapped back and forth between which of the lvl 3 and 6 features should be first. Shadow monk has the precedent for having pseudocasting for 2 ki. Either way, both abilities currently use ki, which I don't particularly like. Ki palm sigil is balanced on the assumption that most cantrips are just a bit better than one unarmed attack (for example firebolt, which deals 5.5 damage is the same damage as an unarmed strike).

The 11th level is a more customizable AOE option since monks don't really have one. Its balanced assuming a couple of targets in the area of effect - it should be worse than attacking 2 targets (compared to flurry) but better for attacking 3. I can increase the power budget a bit for the situational option of charging an attack.

The last level is pretty trope-y.

Anyway, without further ado...