Mage is the Class that specialized in different strong-power kinds of magic (Actions that deal damage to all creatures (Ice Storm
Fire Storm
Firebolt
Lightning Bolt
Scouting Patrol
Imperial Reinforcements
Divine Fervor
Fifth Legion Trainer
You’ll be able to combine casting powerful AOEs like legendary Dawn’s Wrath or point removals like Piercing Javelin
Kvatch Soldier
Hive Defender
Auroran Sentry
Lightning Bolt
Camlorn Sentinel
Cloudrest Illusionist
Miraak, Dragonborn
Indoril Archmage
Ayrenn, Dominion Queen
One of the most powerful and top decks now are Control Mage decks. For example:
Deck «Control Mage»
Netural cards
Intelligence cards
Willpower cards
There are a lot of good AOEs (Ice Storm
Firebolt
Lightning Bolt
Kvatch Soldier
Hive Defender
Auroran Sentry
Dres Tormentor
Shrieking Harpy
Indoril Archmage
Odahviing
Miraak, Dragonborn
Piercing Javelin
Healing Potion
You can also build Midrange decks when you use this class. For example:
Deck «Midrange Mage»
Intelligence cards
Willpower cards
You can play a lot of creatures and give them all buffs(two Ongoing effects by Divine Fervor
Imprison
Imperial Reinforcements
Cruel Firebloom
Brutal Ashlander
If you play an aggressive game you should be able to build an Aggro Mage deck.
Deck «Aggro mage»
Netural cards
Intelligence cards
Willpower cards
Dunmer Nightblade
Steel Sword
Camlorn Hero
Divine Fervor
On Arena this class is one of the most popular because of strong unique summon bonus effects of the cards. But you must follow magicka curve and potential synergy between cards. Also you should draft actions and mass removals to control the board.