Hello,
When you put Ithlinne Aegli into play her deploy is to "boost a Scoia'tael unit in your hand by 4".
This works on everything I have ever played (which is a green Scoia'tael card) except Saesenthessis, which is also a Scoia'tael card.
As an extra reference point, Milva when in play "Boosts self by 1 whenever you play a Scoia'tael" unit and does work when Saesenthessis is played.
When you put Ithlinne Aegli into play her deploy is to "boost a Scoia'tael unit in your hand by 4".
This works on everything I have ever played (which is a green Scoia'tael card) except Saesenthessis, which is also a Scoia'tael card.
As an extra reference point, Milva when in play "Boosts self by 1 whenever you play a Scoia'tael" unit and does work when Saesenthessis is played.