If the mana bar is still present in the HUD states I'd like to propose some basic spells be added as a default item for every player at the very least.
Perhaps mana could be handled like this- you regenerate it at 5 points every second in a pk area, plus 5 more if sitting, 5 more if in a protected area and 10 more while laying in a bed.
The first spells could be...
1. The fireball weapon. It could expend 10 mana for a simple unblockable projectile.
2. A healing spell. It could heal 2 hearts to you and guild members nearby for 50 mana.
3. Mark/ Recall. Set a location to teleport to, then do so for all 100 of your mana. Disabled in certain areas such as the Nexus or seasonal levels or any other level considered temporary.