I'm looking to build the new [[Sab-Sunen, Luxa Emodied]] What are some of the best counter manipulation cards?

This card design is so awesome and evocative to me, I love the restriction element to it forcing me to be a little careful about how I dispense my counters. Seems like generic counter doublers will be quite weak/counterintuitive. Im trying to keep it water and frog themed so bonus points if they hit one of those criteria.