Scenario
A party that has a Rod of Absorption is facing an evil Sorcerer. The Sorcerer casts a twinned Ray of Sickness at the Fighter and the Wizard. The Wizard is holding the rod.
Would the Ray that is targeting the Wizard be able to be absorbed?
I am unsure whether Twinned Spell Metamagic creates a second spell using the same slot, thus able to be absorbed, or if it is a single spell that now targets two creatures.
Rod of Absorption:
While holding this rod, you can use your reaction to absorb a spell that is targeting only you and not with an area of effect. (DMG, p. 195)
Twinned Spell
When you cast a spell that targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell. (PHB, p. 102)