The Kaiser series are only useful if the one you've pulled matches your team element (giving you a decent active skill but low base stats) OR you can limit break it past 40. Otherwise the LV40 stats are somewhat lower than LV100 event SSRs. I added it to the Eidolon tab of my spreadsheet if you want to check out the stats at various levels yourself.
Also, I don't know if I can stomach the constant browser crashes that have accompanied this event.