Max-Min maplestory Tower of Oz for phantom

Hi Everyone,

I recently made it to floor 33 on tower of oz with my phantom (3 pill slots, looking to hit floor 40 after I unlock the 4th pill slot today!!); however, I felt like my mobbing was very inferior in tower of oz, especially in stages where you are required to kill 200+ monsters that spawn in tilted and spaced ledges. I was using Showdown with prenombre and the phantom teleport skill but I feel like I can use a different 4th job skill to maximize efficiency. I stole Chain Lightning yesterday (I choose that over Cannon Bazooka because some maps aren't flat at all and I feel Bazooka has a really really long delay despite its great range) but never got around to testing it yet. Any ideas which skill to use for mobbing? Doesn't even have to be 4th job skills!

Here's what I was thinking could be viable:

Cannon Bazooka

Chain Lightning (currently using this one)

Piercing Arrow (is this better than cannon bazooka?)

Showdown (allows for easy jump attacking, extra drop rate, and fast cast time)