Kelya is usually around x5 to x10 the cost of Tarsa to rent. He's probably worth it and I could give him a run at the lower end, but at the higher end he'd take up 40% of the budget for a Splinter - which doesn't leave much room for good monsters.

I was tempted to build a Water deck around Possibilus, but he's rocks and diamonds so I prefer him in very specialized battle conditions.