If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Use the elements to lob attacks at your enemies, summon elemental, and rock the pants off your former apprentice. Which elements you use play a big factor in your success- use the correct element to deal maximum damage? Have a fire elemental you want to make stronger? Cast some fire spells on him- just be careful not to hit the enemy fire elemental with fire spells or you'll heal and boost them.