After what Kanada had said about his ability to use Holy power and important the ability was to the rest of the cosmos, Lenny had decided not to use it, especially not in front of the Sisters of Eve. Besides, he was sure that none of the sisters of Eve would have a favorable impression about him.
Also, they were extremely smart. If they figured out that he was connected with the Morningstar, who was the reason for their down fall, then Lenny was sure that at least one of them if not two would want to take revenge.
Lenny on his own was never one to fear a fight. However, to say that he was not wary of these sisters would be an absolute lie.
After all according to Appraisal, they read as ordinary humans with no demon rank whatsoever. However, their level was abnormally high.
Also, their other skills were hidden.