Hmm...the no cooldown thing works if it's implemented correctly. For example, from a strategic point of view using too much chakra at once would have serious effects in the long term of a battle or whatever, so it would be best to conserve chakra and use the right amount at the right time. To counter "spamming", chakra costs should exponentially increase per amount jutsu used in a certain amount of time. *I use Jutsu A, which costs 500 chakra. Then immediately after I use Jutsu B, which costs 600 chakra normally, but I used it within the same timeframe I used Jutsu A so the chakra cost goes up a lot; to like 900 chakra for instance. Maybe the timeframe can be passive influenced meaning players have the ability to decrease the "no spamming" timeframe over time with the use of points.