Having Kagenui and Chicken Knife definitely makes the difference, compared to having a Thunder Rod to guarantee 9999 damage. Without both those, you'd have to do more than just block Almagest; you'd also have to equip Aegis Shield to block Meteor, and hope that Neo Exdeath doesn't spam Dispel and a physical to smack you. Suppose this could also be done in the SNES with Aegis Shield, but I don't know if you'd get in trouble for not having Kagenui. In any case, you'll need to rely on luck if you want to try this in the SNES version.