Stable
From Portals of Phereon Wiki
A genetic trait that increases the number of permanent effects that can be used on a unit by 5, it also increases the stability of the eggs they make. What you really want is the increased item use, even on breeding characters. Even if you don't want to risk a Mutagen, 5 extra uses of potions make a big difference, whether they're Energy Potions or Potential Potions.