Blissey, while not resistant typewise to anything that matters but Ghost, is also not weak to too much in Ubers (Fighting isn't as common as Giratina's four weaknesses tend to be). Typing is also what saves Dia
As someone who have played FRLG a lot in the past, Jynx is by far my favorite pokemon to use in game. In FRLG, Jynx is obtained when traded with Poliwhirl, which can be caught after defeating the Snorlax on route 12. It's fast, OHKOs a lot with Psychic / Ice Beam, levels up...
Fighting-type moves are also super-effective against Sharpedo, Magnezone, and Snorlax, with the latter being particularly hard to defeat due to its large HP. The all-round powerhouse, Dark- and Rock-type Tyranitar, can use its variety of attacks to overcome Alakazam and Mismagius, who don't...
Fixes the Salamence weak with a strong Ice Beam to take him out. Plus he's neutral to Sandstorm, which is always a good thing on a team with Tyranitar. And so Swampert comes in at #6 to complete the team: So there we have it. It is a lengthy process, and the end products ...