A few versions ago it was possible to make angels by becoming slime, shapeshifting every part into angel-slime instead, then enchanting a slime canister to turn you human again, presto, instant angel, these days doing that now will revert all angel-bits to human instead. I have an exported character (Natalie, mid 30s futanari) that is an angel that I import via the auction house in Slaver's Alley to all my other characters, then use her (either having her impregnate my character, me impregnate her) to make more of them, angel+human becomes lesser angel, two lesser angels becomes greater angel, angel+demon becomes fallen angel (yet to find any of the results of that pairing). Attaching said character save, just put it in [game directory]\Data\Characters.