User blog comment:NølesseObliged/Managing Team Advice pls/@comment-25319610-20151214164511/@comment-26926725-20151214194125

Instead of Charis, go Rahgan.

Rahgan provides a good DoT effect on both BB and SBB. His SBB ouclasses Charis'. Rahgan has every buff that Chairs has on SBB, with the addition of a DoT effect, which can be really useful for reaching thresholds without attacking (note that DoT applies after boss' turn). This is really useful since its more damage that is 300% of Rahgan's attack every turn after the boss moves, which means faster clears.

The only advantage Charis has over Rahgan is the BC/HC drop rate buff. Since you will have a hit count buffer, your BC and HC drops will raise naturally with the extra hits (Rahgan will drop 32 BC max, but with extra hit buff, will now drop a max of 62). Add on the fact that you will have a healer/mitigator combo unit and a BB manager on the team (for an ideal boss fighting team) so you won't need the BC/HC buffs from Charis.