How to make Thresh more Risk/Reward.

Remember when Mark/Dash () first came out? And how everyone was complaining that it was OP and ruined the game mode. Well remember how they balanced it? They made it so that half of the damage was applied when dashed to the target. Could it be possible that thresh could deal half the damage when his q was reactivated? This would mean that his damage wouldn't actually be nerfed but in order to take full advantage of it he would have to be risky and initiate into the fight. This would not nerf Threshes utility but I think it would at least make him a little less powerful. Thoughts/suggestions?