1. Scald: A water-type move that has a chance to burn the target. This is Blastoise's primary STAB move and is useful for dealing damage and inflicting a status condition.
2. Hydro Pump: A powerful water-type move that deals heavy damage. This is Blastoise's secondary STAB move and can be used to take down opponents quickly.
3. Ice Beam: An ice-type move that deals damage and has a chance to freeze the target. This move is useful for covering Blastoise's weakness to grass-type attacks and can also be used to set up a freeze lock strategy.
4. Earth Power: A ground-type move that deals damage and has a chance to lower the target's special defense. This move is useful for hitting opponents that resist Blastoise's water-type moves and can also be used to set up a stealth rock strategy.
Other moves that can be considered for Blastoise include Rapid Spin, Toxic, Yawn, and Curse.
Rapid Spin can be used to remove entry hazards from the battlefield, such as Stealth Rock and Spikes.
Toxic can be used to poison the target, slowly whittling down their health.
Yawn can be used to put the target to sleep, giving Blastoise an opportunity to set up or recover.
Curse can be used to increase Blastoise's attack and defense, making it a more powerful sweeper.
The choice of moves will depend on the individual player's playstyle and the team composition.