Just for fun let's compare things.
For now let's compare plain damage.
Kensai:
Kensai I = 1 damage
Kensai II = 1 damage & 4 damage(8 str)
Kensai III = nothing
Total = 6 damage
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Frenzied Berserkerlazy)
FB =
6d6 vicious
3 damage from strength
total minimum damage = 9
I'm going to leave this 1/4 done because I am Several Chickens.
Discuss
p.s. FB still sucks