I think instead of creating a new glyph for the jester, adding him a Gettindare would be better. With a twist:
he can spam it as much as he wants it to, and even gets a 1mp discount for it. But he has a permanent slowed debuff, so casting the glyph would result in him being normal.
I kinda dislike shifty. For a 3rd trait I'd give this:
Unpredictable: You start with a random strike effect, and every time you cast Gettindare it's changed randomly for a new one. Leveling up also rerolls it. Possible effects: knockback, poisonstrike, lifesteal, burning strike, magical attack, corrosive strike. Actual numbers need to be adjusted. The numbers could have some randomness to them too, like once you get 4 poison strike, on a different roll only 2.