Good runes for dot/sustain dmg champions? Can't seem to find a good setup.

Thunderlords was the go to mastery for characters that did dot/sustained dmg and with the new rune system it seems there's really no good keystone for those types of characters. Thunderlords was replaced by electrocute which went from being a good dot-based champion choice to favoring burst champions with 3 quick abilities.

I loved using it on say, offensive based Galio, Garen (though glacial works good for garen now), Rumble, Brand, Swain (R form), etc.

What is a good alternative for those champions now?