Legends of Runeterra has many card effects that are common enough that they get their own keyword - a word or two that immediately tells you how the card works. Let's take a look at the Overwhelm (Spell) keyword.

Guide

You might be surprised to learn that Overwhelm (Spell) functions almost exactly like regular Overwhelm, only it's...on a spell. They are technically different keywords because they need to be phrased differently (there is no "I" when it comes to a spell's text). Other than that, it's just Overwhelm.

Keywords that Work Great with Overwhelm (Spell)

Overwhelm (Spell) is, fittingly enough, a spell-only keyword, and as such doesn't really play with other keywords.

Playing Against Overwhelm (Spell) in Legends of Runeterra

The only existing example of Overwhelm on a spell comes with one that costs 0-Mana, so there's not much that can be done about it. Even if you exhausted your opponent of Mana and spell-Mana, they would still be able to cast Final Spark. Beyond that, try to field high-Health units so that the Final Spark cannot pierce through their defenses.

Example Legends of Runeterra Overwhelm (Spell) Cards

Lux is currently the only example of Overwhelm on a spell, with her Fleeting Final Spark cards. Blast a unit with overwhelming light, and the Nexus too!