Sounds like he doesn't have his deck equipped or possibly has an empty deck.
Just like a hat, you must equip a deck to use it. Once the deck is equipped, make sure he has actually added spells to the deck, and don't forget the Treasure Cards!
Your Spell Deck is where all your Spell Cards are held. You can open your Spell Deck by pressing P on your keyboard, when you're not in a duel. Remember P for Pack of Spell Cards! On the right are all your available cards. This is a deck of an Ice Wizard. If you want to be able to cast a card in a duel, you must add it to your pack, which is shown on the left. To add a card to your pack, click on it.
Your wand automatically places a number of minor bolt spells in your deck, and amulets will often times put a random spell card in your deck. If you have more than one deck, you can scroll through them by clicking the arrows around the deck title.
To put a card inside your deck, simply click on it on the right side of the screen and it will show up in your deck contents. The red circles next to the card shows the max number of copies you can put inside the current deck. The yellow circles show the number of that card that you have already put into your deck.
To use your items, you must equip them. To equip items, select them in your backpack & press the hand icon to equip the item. Items that have the little hand icon are what you are currently wearing. Items that have the little dollar icon were purchased with Crowns. Items that are greyed out, you cannot wear.
If you want the prize, you have to build the ladder rung by rung. There are no shortcuts.
