The TM secret power can be purchased at the slateport city outside market.
There is not a tm for bite or crunch.
Thunderbolt
Yes, Tm's in Pokemon Omega Ruby and Alpha Sapphire are re-useable
Trade.
25
Double Team
you can get it in seafloor cavern
You cannot get the TM for Ancient Power in Pokemon Crystal. Ancient Power has yet to be a TM in any of the Pokemon games.
double team
Location is Route 115
at the game corner
In the Safari Zone