its a TM its in the veilstone pokemart hope i helped
Nope.
There is no HM Flash on Pokemon Diamond, I personally think its been replaced by HM05 Defog.
In Pokemon diamond many Pokemon can learn flash for eg. Electric Pokemon such as Pachurisu Pichu and Luxray all (eveloutions) and yeah just experiment and see what can learn flash!
It's not a HM anymore in Pokemon Diamond and Pearl, but it can be bought as a TM in Hearthome City Department.
Do the same thing in Pokemon peaRL
You can purchase Flash in Veilstone City in the mall in Pokemon Diamond.
At the Veilstone department store (TM90).
no
You can buy TM70 Flash at the Veilstone Department Store.
In Pokemon Diamond the TM 90 is the move substitute.
the hiker is in mt.cornet
Any Pokemon that can learn a electric move