Infinite colored mana that can only be spent to activate abilitiesReturn any number of creatures to their owners' hands
How it works
Activate Crackleburr and two other blue creatures you control by tapping them, adding 1U/RU/R that can only be spent to activate abilities of creatures.
Activate Crackleburr's second ability by paying U/RU/R and untapping it and the two blue creatures, targeting any creature.