You can get it on routes 210 and 215. Be aware it's very uncommon, though.
Go north of solaceon town, then look in the grass by the berries.
Between solaceon town, veilstone city, and celestic town.
You get in route 210 15 but I got a scissor so and I got a garcomp lvl 52 and a dragonair lvl 34 if uw ant a dratini you need to go to mount cornet on the w side on the water you need a super rod it evolvles a lvl 30
You can find a scyther in routes 210 and 215.
You can get him in the tropical forest of zanzibar
Route 210 and 215 are where scyther can be found, just use a metal coat on scyther to make it scizor, if you don't have a metal coat it can be found at the end of iron cave.
I think that there on 210 and 215, But they are UNCOMMON. Metal coat - iron cave- I don't think any trainers have a scyther.
Nagami is correct, however for further questions about the whereabouts of a pokemon an extremely well organized site is pokemon diamond/pearl/platinum marriland and then type the name of the pokemon.
I donot have ening ider but I thinck the ancers other peopie gave me will help don't this this web sight