small edit for clarification: Dark team with Dark Lilim. Other dark eidelons in the team (should they matter in any way) are Jack and dullahan.
Did a Quick test, comparrison Lilim 1596 to Yatagarasu 1773 difference of 177
With Lilim to yatagarasu: on home page 42276 to 42399 : Difference +123 for yata
Mordred: 37539 - 37557 = +18
Satan: 37774 - 37792 = +18
Ren: 36274 - 36292 = +18
Belze: 35074 - 35092 = +18
Added Sol since she is neither dark nor fire: Lilim 35793 - Yata 35970 = 177
Will stick with Yata, the benefit is even with the bonus higher.
edit: got a little mistake at the top, its fixed now.
last edit: Yep Lilim gets +10% to the stat boosts. Rounded down. its exactly the 18 difference.