Council of the Absolute

If you name half of a split card with fuse, and then you cast both halves, the cost reduction will apply to the total cost of the spell. This is true even if the half with the chosen name requires only colored mana to cast.

The last ability can reduce alternative costs such as overload costs.

You can name either half of a split card, but not both. If you name half of a split card, your opponents can cast the other half. If that split card has fuse, your opponents can’t cast that card as a fused split card.