Thank goodness you didn't because that would have been a complete waste if you did. BoH's Berserk skill is a good alternative if you don't have any Takeda Shingen of Kais or any other strong party passive buffers. Her leech skill works great on her simply because she hits hard with her skills buffing her damage. You were going to waste 2 skills for 1 in a case where you should have simply had ToK inherit BoH's 2nd skill.