What about El for elements and EEl is elements minus earth (like in the IV roman numerals). Ne could be Non-elemental, using the same scheme (so NNe is Astral, Death, or Blood).
Therefore WElBS is elements (El) minus water (W) plus blood (B) and astral (A). We could also use decimals to minimize writing: 1 WElBS is a 100% chance of +1 elemental (sans water), blood, or astral. To save the (outrageous) work of writing periods (an extra character, ugh) we could always assume the first digit is the ones place: 01 WElBS is 10% chance for another fire/earth/air/blood/astral.
Two numbers could be used for more than one random, eg: 2-1 WElBS = 2 100% earth, fire, air, astral, or blood randoms.
If we are willing to get more advanced, it could even extend to accomodate different chances, eg: 2-1 + 1-01 WElBS is 2 100% randoms of fire/earth/air/blood/astral and 1 10% chance for a fire/earth/blood/astral.
*whew* I hope I didn't lose anybody there.