OK, all the way through Ultimate. Much easier than Medusa if you kill it fast. PSA: Put Sandalphon or Huanglong as your primary eidolon. The 20% HP will help everyone.
1) Confirmed that the ATK up does not expire after 3 minutes.
2) Overdrive is AOE, 2600 damage to lightning KH.
3) Killed Ultimate Rahab with Siegfried, 32.8K ATK, Ambush extra skill, Baal, Perun, Indra, and Beelzebub (On turn 5). Utter crap!