Hyper Cutter prevents a Pokemon's attack stat from being reduced by an attack from the opposing Pokemon (it can still be reduced by an attack from your own Pokemon that reduces attack).
you find it at the mall
Areana Trap is Trapinch's ability so check its ability. I think some Trapinch may have another ability (Hyper Cutter I think) so just keep catching Trapinch until you get one with Arena Trap.
depends what pokemon it depends if it is a special or physical attacker
Go to the shopping mall on Route 9's TM department. They will be selling the TMs for Hyper Beam and Giga Impact, but they're really expensive.
you have to go to the mall right next to the city right before you go to fight the elite four
No, not all Pokemon in Diamond can learn Hyper Beam.
Hyper Beam.
You can buy hyper beam at the Veilstone Department Store.
No, there are second stage and even basic pokemon who are capable of learning Hyper Beam.
yep every Pokemon can
In Pokemon Crystal, the Hyper Rod can be obtained by talking to the fisherman on Route 32, near the Union Cave entrance. The fisherman will give you the Hyper Rod as a reward for showing him a Red Gyarados, which can be found at the Lake of Rage. The Hyper Rod is a special fishing rod that allows you to catch higher-level Pokemon compared to the Good Rod or Old Rod.
Charmander must evolve into Charizard to learn Hyper Beam.