User blog comment:JmLyan/Zenbakia, the Number Master/@comment-3476718-20130621180359

How about this for R?

Zenbakia marks an enemy champion with Countdown. If the mark is removed within its one second channeling time, the ability is negated, but does not refund the mana cost nor the cooldown. If the channel succeeds, the mark deals 5/8/10% of the enemie's maximum health every second over five seconds. (Totals up to 25/40/50% of opponent's maximum health ). 220/200/180 second cooldown and 300 mana cost.

Should make him less unbalanced, but still retaining the kill-securing feeling Zenbakia has.