gacha

. Which would mean that the remaining ones in the blood sky are Mercury and Mars? Is ORT really the Ultimate One of Mercury?

ORT.
Ultimate One of Mercury (?).
One of the pals of the Ultimate Ones appearing in Notes

...Actually, might not really be the strongest life form that received Earth's SOS sign.

. It has not been described. Along with Type Uranus, it destroyed the majority of the Leaves of Yggdrasil, the Type Venus monitoring base, during the Type Uranus and Type Neptune firing operation.