Train it to Lv25 to evolve it into Haunter, and then trade it to evolve it into Gengar.
Gastly evolves to Haunter at level 25.
Gastly evolves at Level 25.
Gastly evolves at level 25.
Yes
Gastly evolves at level 20 into Haunter
Gastly Lvl.25>Haunter Trade>Gengar
Level 25
25
Gastly evolves at level 22 then Haunter evolves by trading it.
no he does not evolve in Pokemon hg or ss
it evolves at lvl 9001
evolve gastly.