random PSA: If anyone has an Isis and wishes to join the master race, BL Isis, Echidna, Grape Dragon, Siegfried, King Bubblie is the team I currently use and imo is the best team physical Isis can get, especially for non-iap.
The thing is normally while Isis is easy to use and bursts down floors super easy, she has some trouble with bosses since her multiplier isn't that high. But with Grape Dragon + Siegfried you basically get a pseudo chinese active because you still hit 12.25x however most of the orbs are water which is what you need and the result is Isis can actually goddamn burst.
Like without even trying and just poping actives + pulling off 12.25x does at least 2 million damage easy. If you actually set up the board with cascades and stuff to maximize skyfalls then I've hit like 5 million+ bursts.
Also the team has pretty well rounded stats. With everyone lv. 99 and 0 +eggs you have 16k HP and 2.2k RCV. With just the leaders or friend leader (*coughmecough*) and Echinda +297 you have 18k HP and 2.8k RCV.
Oh yeah also you have 4 skill boosts so it only takes 6 turns for echidna to come up. If King Bubblie is max skilled too then you pretty much never have to stall for skills ever.
And of course everyone is farmable, although grape dragon was a limited time thing (it might come back).
If you have Isis but no twinlits for B/L. Use B/B Isis, Echidna, Lilith, Valk, Shynee to beat up twinlits so you can get right to the good stuff.