For those who haven't read His Dark Materials from Phillip Pullman: This is about the race of sapient armor wearing polar bears called Panserbjörn
The concept isn't finished yet, so I'd like to get your input on the basics.
Starting point is a human mage that has become more comfortable in the skin of an animal than as a real human.
1) Communications
I'm unsure if trodes work on animal brains. If they do, this is the easiest solution to take care of communication with the rest of the team.
Alternatively, the Mind Net spell would allow telepathic communication with the team, but it would add another sustained spell to this concept, which is something I'd like to avoid.
Manifesting is another way to communicate without changing back, although you'll have a comatose animal lying around.
2) Survivability
Thanks to Howling Shadows this situation has been greatly improved.
Animal armor is really cheap at 50 nuyen per Armor point. up to BOD+3. Add Bear Mentor Spirit for an additional +2 soak dice, the armor and reinforce spell and you get a very well protected bear.
One essential thing is the Increase Body spell: For a human with BOD 5 to become a Bear with BOD 9 it's necessary to use the spell, since Shape Change only works if you are within 2 points of the body value of the new form.
This trick works by RAW but raises some questions: If you drop the body spell do you forcibly revert to your original form? Does the enhancement bonus carry over to the new form, increasing the value in addition to the points you might invest into the attribute from successes you generated with Shape Change?
Finally, adding the option from the drake chapter for expanding armor allows you to change between a smaller, less threatening form (like a large dog) and your bear form, so you can be part of social interaction (don't forget to get electrochromic modification so you can display "Service Dog" on your sides)
3) Sustain spells
Long term this build needs two initiations: Channeling and Quickening. A channeled R6 Spirit of Men will increase all physical stats below 5 by 3. Also the spirit can cast and sustain two spells on the character (Shape Change and Increase Reflexes most likely). Getting Pain Resistance is also a nice perk.
An R 4 Sustaining focus for Manipulation spells will allow to keep up a Magic Fingers spell, allowing the mage to use door knobs and other such objects.
Getting R3 Focused Concentration is probably also a good idea to sustain other useful spells like Combat Sense or Manascape
4) Stealth
Having so many spells on your person can be a problem with astral perception. Getting Manascape is almost a must, so you can hide your spells and present the aura of a "normal" animal. Other spells like Improved Invisibility or Stealth are also quite useful - as is the good old Concealment power of your Spirit of Men buddy.
5) Costs
Howling Shadows introduced Armor as well as Visual and Audio Equipment for animals. This gear is incredibly cheap. R6 is available for 300 nuyen. Add a persona mod and you get a R6 commlink for 700 nuyen.
Likewise staying in animal form will save on a lot of lifestyle costs - although sharing a lifestyle will be a good idea. Maybe another player wants to play a detective mage and could use a partner in the form of a large dog/whooly mammoth

You probably want some Sustaining Foci, which will be the most expensive part of the build regarding nuyen.
Reagents will also be a regular part of your casting regime, so you can cram in low force spells with strong effects into your various sustaining mechanisms.
6) Spells
So far I have:
- Shape Change
- Increase Reflexes
- Manascape
- Armor
- Reinforce
- Increase Body
- Improved Invisibility
- Increase Charisma
- Combat Sense
- Lightning Bolt/Flame Thrower/Acid Stream (you won't be holding a gun in your paws, so be ready to sling some ranged spell), limited to a fetish
- Mana Barrier (A good way to protect from enemy spells and dispells)
7) Skills:
- Unarmed Combat (Tooth and Claw style)
- Spellcasting (Manipulation)
- Summoning (Spirit of Men)
- Perception
- Stealth (Urban)
- Outdoors skill group
- Gymnastics (Climbing)
- Running (Optional, but probably a good idea)
Doable with Skill Priority B and Magic A
9) Qualities
- Focused Concentration 3
- Agile Defender (Pushing AGI is pretty easy with this build)
- Superhuman psychosis (Fitting for someone who is more animal than human)
- So Jacked Up (Needs a bit of refluff, but decreasing logic while being transformed sounds very fitting)
-


Problems
Already mentioned: A shitload of sustained spells are needed to be combat viable. Guardians and mana barriers will be a real chore. One solution would be to be an elf and take a CHA tradition so you can benefit from increased drain soak and a high chance to wriggle through mana barriers without setting them off (or getting your spells knocked out) Increase Charisma would be a good idea also. The social life will probably be a bit limited, but that is part of the concept .
I'll probably have trouble finding enough skill points. You can skimp a bit on Attributes, but you'll need max BOD, WIL, CHA, INT and maybe a bit of LOG also.
Suggestions so far?