A thought on Thunderlords

I know Riot wants to see how the current keystone mastery changes go. But we're still talking about overall the only damage keystone of it's place. It will always be the most picked option.

To fix it's toxicness(some champions easily proccing it). Make the effect a debuff that effect the next hit on the target.

So say Brand lands his W. Procs Thunderlords. It debuffs his enemy so that his next attack, AA, spell, active item, Ignite. Whatever. Deals the damage.

He can no longer land one spell and walk away. He has to get into the fight. This also gives the keystone counterplay. If you see it proc on yourself, you can back off to avoid taking any more damage. Another problem it has.