Tribute 1 "Uizado" monster, and Negate the activation of that Spell/Trap or monster effect
Nin is also a pretty solid card, but for the most part you'll be spending your mana on playing pingers and pingers' tools, so there wouldn't be much left over to dump into her ability
(3) Once per turn, when a monster(s) is destroyed by battle and sent to the GY: You can target 1 Therions monster in your GY
Ral, Monsoon Mage / Ral, Leyline Prodigy Ral, Monsoon Mage feels like a classic coin flipping card, where there's an actual positive and negative result
There was a different rule in place regarding what happens when a player has unspent mana back when cumulative upkeep was still being printed
I personally like not knowing what the random one is so get someone else to draw it for me and tell me if it is permanent or not