Warframe: Caliban and Ivara

The half sentient and the archer.

Caliban

Only after completing the New War can you start collecting parts for Caliban from Narmer bounties, but don't be too annoyed if the blueprints don't drop too quickly because you'll need a lot of those Narmer isoplasts that also live in the same reward table to build him, as well as anomaly shards you can only get from Veil Proxima using your railjack. It is quite a lot of work to get all the things you need!

Your reward is an odd looking frame who can spin like a top, stomp for some AoE, summon a sentient melee ally or do a quick, arcing beam blast - none of which feel very unique nor useful. The ally is ho hum, and there are other frames that do those other abilities better. Not a good warframe at all and definitely just mastery fodder for me.

Ivara

You have a slim chance to get Ivara's blueprints in any spy mission, provided you unlock all three vaults in a single run so unless you are super lucky and/or patient (I was only lacking 1 part after completing Steel Path and Empyrean space), you may have to grind a little to get her and like Loki she is designed as a stealth frame. It's nice that an enemy radar is included as her passive.

While she can only turn invisible if walking, her ability to do so is an on/off toggle unlike Loki's activate every 20 seconds or so (so he does become visible while recasting). She can also pickpocket extra loot while doing this which is a plus. All her other abilities are bow related since she is "the archer" after all: she can summon an exalted bow, control the trajectory of her projectiles, and pick from a bunch of trick arrows (noise, sleep, stealth or wire) at her disposal.

Pretty neat, but definitely designed for a slow and methodical pace. To that I ask, have you played Warframe lately? If you aren't solo the odds of a slow and methodical pace happening are near zero. My biggest problem is she can't regain energy while stealthing so while she can sustain her invisibility until her power runs out - it will run out eventually. Comparatively my Loki actually regains energy while invisible or if you are a Wisp then simply continually jumping or bullet jumping means nothing can see you. Cool frame, but I've already got ones that cover her niche.