User blog comment:KenshinFoxz/Help Me!!!/@comment-36.79.231.105-20141209063146/@comment-24.185.205.180-20141210042052

35 combo Light attack on random enemies, 40% boost to ATK of all allies for 3 turns (5* Len)

http://bravefrontierglobal.wikia.com/wiki/Deity_Ruler_Lucca

just scroll over the underlined atk buff in Lucca's SBB and you will see that it is 100% which is much better than the 40% offered by Len's 5*. In the long run, Lucca is better so I see no reason in even considering Len with his random BB.