Erdok’s True Strike

You point a finger at a target in range. Your magic grants you a comprehensive insight into the target's defenses. You learn the targets Armor Class. On your next turn, you gain advantage on your first attack roll against the target, provided that the target is still within the spells range.

The spell grants a greater insight when you reach higher levels: you learn all of the target's resistances at 5th level, all immunities at 11th level, and all saving throws at 17th level.