The Lv. 100 stat for exp. is 1,640,000. He is among one of the most difficult pokemon to raise to Lv. 100.
To get Metagross, beat the E4, go to Mossdeep City, into steven's house and collect a Beldum.
At Lv. 20, it evolves into Metang, which learns confusion and metal claw at lv. 20. At Lv. 45 Metang evolves into Metagross! Metagross and metang learn the same moves, so evolving only gives more power.
Ditto is the breeding wild card. He will breed with Beldum/Metang/Metagross.
I had no issue with Metagross, but stopped at 50 so I could use him in battle frontier and battle tower.
You may have wanted to evolve Metang at 50 so he could have knew Meteor Mash.
I thought images could be 250 pixels high? But in sigs the height limit is 200?