Sobaru & Beti arrived in Anime Origins as one of the update’s Mythic banner units, sitting alongside Emmy and Jollus. It is a Hill unit, so it covers the airborne waves that wipe ground-only teams, and its evolved form leans hard into damage-over-time pressure. Getting there takes two separate grinds: one for evolution materials, and one for the trait roll everyone actually wants.
Quick answer: Evolve Sobaru & Beti into Sobaru & Beti (Forbidden Library) using 20 Azure Remnants, 15 Violet Remnants, 1 Radiant Remnant, 3 Promethe Remnants, 15 Cursed Beast Horns, and 1 Book of Wisdom. Cursed Beast Horns drop from Legend stages in Library of the Dead Afterdark, the Book of Wisdom comes from PLD-1 artifacts, and Immortal is a 0.1% Secret trait roll.
How to get Sobaru & Beti from the summon banner
Sobaru & Beti is a Mythic pull from the update banner, which also carries Emmy and Jollus. There is no quest or story unlock for the base unit, so gems are the only route. Bulk 50x summons are the practical way to burn through the rate, and the same pulls feed you duplicate Mythics for later fodder.
The wider update also added Rainu Harto as a Secret, Shali as a Mythic, and Prisla and Kenshen as Legendaries. None of those are required for the evolution, but they share the same gem pool, so plan your spending before you commit.
Sobaru & Beti (Forbidden Library) evolution materials
The evolution screen lists six requirements. Remnants are the shared currency across most Mythic evolutions in the game, while the last two entries are the ones that actually gate you.
| Material | Amount |
|---|---|
| Azure Remnant | 20 |
| Violet Remnant | 15 |
| Radiant Remnant | 1 |
| Promethe Remnant | 3 |
| Cursed Beast Horn | 15 |
| Book of Wisdom | 1 |
Note: Jollus and Emmy have their own separate recipes, and Jollus needs Sixfold Spirit Crystals rather than a Book of Wisdom. Do not stockpile the wrong item because a friend told you it works for both.
Where to farm Cursed Beast Horns and the Book of Wisdom
Remnants come in through general play and codes rather than one specific stage, so they usually finish long before the Book of Wisdom does.
Pleiadys Tower and Shali’s Stash
Pleiadys Tower is the update’s other progression track, and Shali’s Stash inside it sells blessings and evolution items. It is worth checking the stock before you commit to a long artifact grind, since a purchase can cover a gap in your remnant count.
The tower runs on a parry system, and dying triggers Return by Death, which sends you back rather than ending the attempt outright. Expect to lose runs while you learn the timing.
Codes for Trait Rerolls and Stat Prisms
Three codes are live with the update, and two of them exist almost entirely to fund trait and stat rerolls. Redeem them before you touch a single reroll, because chasing Immortal without a stack of rerolls is not going to happen.
| Code | Rewards |
|---|---|
RBD! | Gold, Azure Remnant, 5x Radiant Remnant |
AuraMonster | 1,111 Gems, 11x Trait Reroll, 11x Stat Prism |
UpdateUno | 10x Trait Reroll, 10x Perfect Stat Prism, 10x Stat Prism |
Codes are case sensitive, and RBD! includes the exclamation mark. That one also hands you the single Radiant Remnant the evolution asks for, several times over.
How to roll the Immortal trait
Immortal is the game’s Secret-rarity trait and lands at roughly a 0.1% chance per roll. There is no pity system and no way to target it, so the only method is volume.
What Immortal actually does
| Effect | Value |
|---|---|
| Damage | +200% |
| Cooldown | -15% |
| Range | +20% |
| Income | +25% |
| Placement limit | 1 |
| Team limit | 1 unit per team |
| Once per match, after Wave 10 | Restores base power, instantly kills nearby non-boss enemies, knocks back and slows the rest |
| Attack effect | Inflicts Decay; enemies that die while decaying explode for 15% of their max health to nearby enemies |
Because only one unit on a team can carry Immortal, it belongs on whichever unit you actually place every run. On a Hill unit like Sobaru & Beti, the range bonus does real work against flying waves. If Immortal never shows up, Overseer and Decay are the sensible fallbacks for a damage-over-time unit.
Level and stat prep before you evolve
Feed food items to push Sobaru & Beti to level 70 before the evolution. Stat rerolls are separate from trait rerolls and use Stat Prisms, with Perfect Stat Prisms giving the cleanest results; triple SS is the ceiling worth aiming for. Do this while you are still farming the Book of Wisdom, since the two grinds run in parallel.
Confirming the evolution worked
Once all six materials are in your inventory, the Evolve button on the unit’s page stops being greyed out. After confirming, the unit is renamed to Sobaru & Beti (Forbidden Library) in your inventory and its art changes, which is the clearest confirmation. Its passive list also updates to three entries.
If the button stays locked, the cause is almost always a missing Book of Wisdom or an incomplete Cursed Beast Horn count, since those are the two materials with no shortcut. Check the exact quantities on the evolution screen rather than assuming a run credited the drop.
Sobaru & Beti (Forbidden Library) passives
| Passive | Effect |
|---|---|
| Murak | Every 8th attack deals 25% of damage as bonus magic damage and suspends enemies for 5 seconds; bosses are slowed by 30% for 3 seconds instead |
| Mana Lock | First attack applies Wound for 8 seconds, cutting enemy healing by 80% |
| Forbidden Library | +2% damage per wounded enemy in range, stacking up to 8 times for +16% |
The three passives feed each other. Mana Lock applies Wound on contact, Forbidden Library converts every wounded target in range into a damage stack, and Murak provides the crowd control that keeps enemies inside that range long enough for the stacks to hold. Pair that with Immortal’s Decay explosions and the unit scales with crowd size rather than falling off against packed waves, which is where it earns its slot in Shibuya Metro Rift runs and similar dense stages.
