Per the ability text of "Hear Me, You Will":
If there is more than one ally present at the start of battle, target other Sith ally gains Dark Master's Training until the end of battle, which can't be copied, dispelled, or prevented.
However in the marquee event you can see the Ronin does not gain this effect even though the conditions are met. According to the ability mechanics visible on swgoh.gg the check is coded as "number of allies > 2".
