Panpour: - C Tier
Availability: Santalune Forest , relatively easy.
Stats: Panpours got very decent speed and good mixed attacking stats that only get better once you've got access to a Water Stone. I didn't evolve mine until near the end of the game but you have access to a Water Stone through secret training from the get go.
Typing: Panpours another bog standard water type competing with the likes of Froakie and Squirtle for a spot on the team.
Movepool: Panpours level up pool is rather limiting it'll only have Water Gun before it gets Scald at level 23 after that its only notable moves are acrobatics in the 30s and Crunch in the 40s, you really should evolve it before getting anywhere near the level you get Crunch. Waiting for acrobatics may be worth it however.
TM wise Simipour & Panpour both get loads of useful moves such as Ice Beam , Dig , Rock Tomb , Shadow Claw , Grass Knot and of course Surf and Waterfall. This gives a good amount of coverage.
Major Battles:
Gym 1 : Solid option for helping out but its movepool is too shallow at this stage and it doesn't possess any super effective moves.
Gym 2 : Has the type advantage here but Tyrant is neutral to your stab and you don't fair too much better against Amaura
Gym 3 : If you've leveled up enough you can have acrobatics to help out.
Gym 4 : You should be evolved and have learnt acrobatics by now, this really helps however Gogoat can survive a hit and Jumpluff will likely outspeed.
Gym 5 : Stay away, Simipour can help against Magneton if you've got Dig/Power-up Punch/Rock Smash but generally won't do much this fight.
Gym 6 : Not a power house here by any means but has some coverage options to help.
Gym 7 : If you've got Crunch on your moveset you can deal a lot of damage to this gym.
Gym 8 : If you have fighting coverage you can take out the snowman and the snowflake rather quickly.
E1 (Fire) : Can handle this easily with Surf.
E2 (Water) : Not much help here.
E3 (Steel) : Not much help here but with between Surf , Dig or Low Sweep you've got enough options to keep your self relevant.
E4 (Dragon) : You've got Ice Beam by now and can solo this one. Noivern is fast enough to outspeed you
Champion : Ice Beam hits 3/8 Super effectively. Surf or Low Sweep can hit Amaura. Against Gardveoir your not much use though Crunch & Surf will do a decent amount of damage.
Team Flare (General) : The fire types are easily disposed of. The Crogunk always seem to have anticipation so your free to spawn water moves against them. You can get Acrobatics to dispatch of Scraggy.
Team Flare (Boss) : Can handle yourself relatively well if you've got a set something like Acrobatics / Ice Beam / Surf / Low Sweep. Meinsho can outspeed and Gyardos can intimidate you reducing your effectiveness. Pyroar and Honkcrow are none issues.
AZ : Can slow this fight as long as you have Surf & either Crunch or Ice Beam.
Additional Comments: Levels up rather quickly but needs a little babying through mid-game. Once its learnt Acrobatics or you've got the TM for it you can evolve him without missing out on much.