Item effect concept: The opposite of Spellblade

I'm sure most, if not all of you know what Spellblade is.

Using an ability empowers your next basic attack with bonus damage on-hit.

What if there was an item that basically did the opposite?

Attacking with this item applies a mark to the target, then activating an ability will consume the mark for extra damage and/or an additional spell effect.

There could be several tweaks made to this for balance.

• The mark could only apply to the last target struck with a basic attack

• The mark could only be applied to champions and epic monsters, maybe include large monsters and pets.

• The mark could only be consumed if that target receives damage from an ability. -- This could even be triggered by allied abilities, making this kind of interaction be useful between ADC and Supports

This is really just an idea for a passive that could be placed with an item. I haven't come up with an item and/or the actual effect yet.

Feel free to share some of your ideas for this, and feel free to use this idea for yourself.

If you do use this passive for your own item, it would be cool if you could link the post here.