Rune Central

Increases your damage and run speed by 50% for each application...also causes you to lose 5 health per second for each application. (So, Kaio-Ken x5 would cause you to lose 25 health per second. Rune-use to activate and to add a new application, rune-delete to deactivate, deletes rune if inactive.

25 health a second? I know RL reload time is 0.8 seconds, but you won't get that many shots off...

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a random mod server: zop.runequake.com

The numbers probably need to be tweaked, maybe more like 2 health per second. There won't be a cool-down on the rune, so you can activate it and deactivate it whenever you want. The point of the health loss is to make it more difficult to keep it active for longer periods of time.