You gain the ability to cast more potent spells.
Spell Slots
The Bishop Spellcasting table shows how many spell slots you have to cast your level 1+ spells. You regain all expended slots when you finish a Long Rest.
Prepared Spells of Level 1+
You prepare the list of level 1+ spells that are available for you to cast with this feature. To start, choose three level 1 spells from the Wizard spell list. Burning Hands, Grease, and Shield are recommended. The number of spells on your list increases as you gain Warmage levels, as shown in the Prepared Spells column of the Bishop Spellcasting table. Whenever that number increases, choose additional spells from the Wizard spell list until the number of spells on your list matches the number on the table. The chosen spells must be of a level for which you have spell slots. For example, if you're a level 7 Warmage, your list of prepared spells can include five Wizard spells of levels 1 and 2 in any combination.
Changing Your Prepared Spells
Whenever you gain a Warmage level, you can replace one spell on your list with another Wizard spell for which you have spell slots.
Warmage Edge
You can use your ValdaSpire24 feature to improve the damage rolls of level 1+ Wizard spells as if they were cantrips. If you add ValdaSpire24 to the Magic Missile spell, you improve the damage roll of only one dart.