Killer Bee made Raikage remember, what his true source was for being the person he's right now. It's true that Killer Bee owned Raikage with lariat, but Raikage's forgot that Killer Bee took his words, as his primary goal. Killer Bee's intention was from day one, to own his brother in lariat, for letting him know.. how strong he become with those words that he has spoken by the waterfall.
It's the same way, how Naruto summoned Kage Bunshins, when Iruka saved him and said that he understood Naruto's pain and loneliness etc. It's also not a suprise, if you ask me; the previous generations owns the next generations. The love that the current generation gets from the previous generations, makes them STRONGER
and it's also the key for protecting the ones they love in the future.