https://tos.neet.tv/skills/40506
Basically, it adds soul property each matk based hit equal to minmatk × (0.5 + ([Skill Level] × 0.03))
So at level 5 it adds 65% of your min magic attack to your spells, at lvl 6 with DM it’s 68%.
It multiplies said amount by 1.5 if it’s a soul property skill, aka only for Possession, Out of Body and Astral Body explosion.
OoB now does quite decent dmg, but the 0 def drawback still makes it really annoying. (healing factor & methadone work wonders though.)
In terms of gameplay, just buff up prior to your BDS>Incin whenever possible as the sheer amount of hits makes it preferable over Sadhu’s own skills.
Laima or melstis help keep it up much better, but that’s up to you if you want it.
Not sure if there are even Transmit Prana gems atm…