Whenever you tap an untapped creature an opponent controls, you may pay . When you do, choose one —
• Create a 4/4 white and blue Elemental creature token.
• Put a +1/+1 counter on each creature you control.
• Scry 2, then draw a card.
Hylda rewards you for tapping down your opponents' creatures: every untapped creature you tap triggers her, and for you snowball into 4/4 Elementals, anthem counters, or card draw. You stall the board with mass-tappers and ramp into repeatable tap effects, then convert those triggers into an overwhelming army or a wide counter-pumped board that closes the game.
Each tap trigger is value, so a single mass-tap effect can fire Hylda many times in one turn
Doubles as defense and offense—tapping creatures blunts attacks while you build a board
Three flexible modes cover tokens, anthem, and card advantage in one engine
UW gives access to premier tap effects, protection, and board wipes to recover
Triggers cost each, so without ramp you can't pay for big tap turns
Heavily commander-dependent; removal on Hylda stalls the whole engine
Modes only fire when YOU tap opponents' creatures—untapped attackers tapping themselves don't help
Slow to start and weak to fast combo decks that ignore the board