Chaos Zero Nightmare: a rate-up Partner is guaranteed, a rate-up Combatant is not
Both banners guarantee an SSR by pull 70. On a Partner rate-up that SSR is always the featured Partner; on a Combatant rate-up the featured slot is only 67% of SSRs, and nothing guarantees her.
A featured Combatant in Chaos Zero Nightmare costs about 70 pulls on average, and there is no pull count at which she is certain. A featured Partner costs about 47 on average and is guaranteed by pull 70. The two banners share the same SSR rate and the same guarantee. The difference is what the guaranteed SSR turns out to be.
The SSR ramp both banners share
All 23 Combatant rate-ups on record and all 23 Partner rate-ups run the same SSR curve. It is a ramp, not a step. The rate sits flat for most of the count, then rises on every pull until the guarantee.
| Pull since your last SSR | SSR chance |
|---|---|
| 1 to 57 | 1% |
| 58 | 5.5% |
| each pull after that | +4.5 points |
| one pull before the guarantee | 55% |
| 70 | guaranteed |
Averaged over the whole cycle, that works out to 2.143% a pull, or one SSR every 47 pulls. 56.4% of cycles reach the climb without an SSR. Only 0.55% get all the way to the guarantee, because the climb makes each pull after that point much more likely to hit. Separately, every 10 pulls guarantees SR or better. That floor never produces an SSR on its own.
Where the two banners split
On a Partner rate-up, the featured Partner is the whole SSR pool. Every SSR the banner gives you is her, so the pull-70 guarantee is a guarantee on the Partner herself.
On a Combatant rate-up, the featured slot takes 67% of the SSR budget. That is 1.429% a pull. The rest goes to the standard SSR pool. That share is better than the usual 50/50, but no loss is ever carried forward. Every SSR is a new roll at the same odds, so no number of pulls guarantees the featured Combatant. Her average cost, 70 pulls, happens to sit near the guarantee number. It is still an average and not a ceiling.
Pulling the full 210 on a Combatant rate-up still leaves 1.7% of players without the featured Combatant.
The chance of having at least one copy by a given pull count, from a fresh counter, with the ramp included:
Before the guarantee the Combatant column trails, because only part of each SSR counts toward her. The real split comes at pull 70. The Partner column reaches certainty there. The Combatant column keeps climbing slowly, and 7.1% of players still have no copy after 140 pulls. Both banners take the same currency: 1 Signal Amplification Anchor per pull. For saving, that makes a Partner a fixed price and a Combatant a spread.
Neither rate-up banner has a spark. Only the standard Combatant Rescue carries one, at 300 pulls.
What the Combatant costs after she arrives
Getting her to the Combatant level cap of 62 takes 840,500 EXP. A Partner caps at 60 and needs 346,000. The 5 Ascension steps cost a Combatant 1,000,000 credits in total, and the last step alone costs 500,000. They add +80 ATK, +30 DEF and +20 HP. Every Combatant gets the same bonus, so Ascension adds to a unit's own stat line without changing how units rank against each other. A Partner's full Ascension costs 400,000 credits.
The banner list shows every rate-up and which character it features, and pull odds lists the exact per-character chance on each one. The full step-by-step costs, including the materials, are on the Ascension and level cost pages.