RockMan Zero [GBA]
You can get a slightly easier game. If you finish the game and save after the credits, you can begin a new game with all of your old equipment, though they won't be leveled up yet. This means you can start with the upgrades from cyber elves in effect, like double life gauge and protection from spikes.
It is possible to obtain this very rare cyber elf, but I didn't say it was easy. Play through Hard Mode and collect (as well as power up to the max) every cyber elf, as well as getting Ranking A or S on every mission. If you start a new game from that saved game, you'll begin with every cyber elf, including Jackson.
Starting a game in Hard Mode
After completing the game, you can start a new game in Hard Mode by holding the left shoulder button down while starting a new file. In Hard Mode, weapons do not gain levels, and bosses have new attacks.
Easy weapons level-ups:
After completing the introductory level where Zero gets his Sword and Pistol, get on the teleporter and teleport back to the base. Immediately exit the place by trying to climb the ladder you are in front of. Ciel will talk to you, and give you several options to select. Keep selecting the first choice she gives you on each option and you will be teleported to a junkyard level. In the middle of the level there will be these pillars that will keep growing back after each segment is destroyed. You can keep destroying the segments with the Sword and Pistol and they will level-up. Keep destroying the segments until the Sword and Pistol are at their maximum levels.
Once getting passed the challenge of getting Jackson, Ultimate Mode is a bit easier to unlock. Simply hold R when selecting a new game after playing through Jackson Mode and using every cyber elf to play Ultimate Mode. Though the name suggests otherwise, this mode allows you to start with all of your weapons maxed out and with the effects of cyber elves already in place; permanent cyber elves no longer effect ranking. Also, you can now perform any of Zero's charged attacks without actually charging them. To fire a semi-charged Z-Buster shot, press Down to Forward + B (doing this combination with the Z-Shield equipped will use a charged Z-Shield throw). To perform a charged Z-Buster shot, press Down to Forward, Down to Forward + B. To perform a charged Z-Sabre slash, press Forward to Down + B. To perform a charged Z-Rod swing, press Forward, Down, Down-Forward + B.