Vault 11: Voters Dilemma Even without extra synergies to exploit, I think this deal is generally very favorable: you get to make some free tokens and then destroy at minimum two of the most dangerous creatures on the board, ignoring shroud, hexproof, and even protection
C Common Guardian Kay'est X WATER Level 4 [ Sea SerpentEffect ] ATK 1000 DEF 1800 Cannot be Summoned unless you control a face-up "Rod of Silence - Kay'est"
Each of these offers a very simple effect: add one mana of a particular color to your mana pool
The way they're played is to stall with Chansey while attaching a Fire Energy to Moltres every turn and then scooping Chansey up when it gets too much damage, using Wildfire, putting Chansey back down, scooping Moltres up, putting Chansey out, attaching Fire Energy to Moltres, etc
Bear in mind notes regarding bans and restrictions