Izanami basic attacks count as AOE attacks with life steal only being 33% efficient.   Basic attacks also don’t scale to 100% on every hit, 80/20 is the ratio.  Time for some maths on how much life steal you gain.

100 = physical power.

10% lifesteal

x = 33% coefficient

80 ÷ 10% – x2 = 4.8

20 ÷ 10% – x2 = 1.32

4.8+1.32 = 61.2

38.8% less compared to other hunters