Galvantula, can create electric webs to ensnare prey and/or other competitors; can help get me to high ground in the case of a flood or a horde of Pokemon that are unable to climb trees; Only weak to Rock and Fire, and with Compound Eyes means only those with Lightning Rod, or that resist Thunder will be able to get close.
Trevenant, whom can help me hide in a forest easily; can cure himself of any status conditions or recover berries to lengthen survival; Phantom Force, assuming the battles are in real time, allow him to get off an attack without taking damage, while Leech Seed can trap and drain almost any Pokemon, making them an easier target; Giving him Double Team can possibly trick a potential foe into revealing themselves and allowing us to get a sneak attack in with Phantom Force.
Abomasnow, whose Snow Warning forces everything around to deal with the cold as well, and can possibly aid in tracking other competitors, possibly even tricking them with fake tracks; His tree design would enable me to get the jump on any Dragons, by blending in with other trees, the snow, or any combination thereof; Though his mass of weaknesses would make having him a tad tricky.
I feel that the Dark type would be the single best type in this regard, as they are Combat Pragmatists by nature, who will use anything they can to their advantage.
Mons that I think would not be very useful:
Tyranitar, whose Sand Stream would function similar to Snow Warning, but also make it annoying for its trainer, who has to keep cleaning sand out of everything, and too little clothing for the trainer could result in serious damage from the Sandstorm alone; If you give him Earthquake, you also have to deal with the colossal vibrations, and risk completely missing a variety of Pokemon that can Fly, Levitate or Magnet Rise themselves.
Any Water type Mon that cannot walk on land. Even assuming they levitate over dry land, there are just so many Water types that the type alone has a high chance of being accounted for, even more so if you can drink, even after boiling it, the water they spew.
Any Mon with a visible flame, as the fire would create some sort of signal giving away your position at all times. Torkoal works too in this regard, despite not having a visible flame but rather a cloud of smoke.
Winner of ares9090's Slaking Award 3DS Friend Code: 3523-3326-1414 (Erek)