Esika, God of the Tree
While playing a standard event I ran across a player that played Esika, God of the Tree on turn 3 with 3 land. As soon as it hit the field I killed it with eliminate. From that point forth all the opponent's land had "tap to add one mana of any color". This appears to be a bug as that is not mentioned in the card text. When they played a second one later their land gained a second line of that same effect. They were able to play spells using mana they should not have had available.
1.) Have 3 land. Play Esika, God of the Tree. Have it immediately removed.
2.) I am on PC, I have no idea what platform they were using.
3.) All their land gained "tap to add one mana of any color".
4.) Only legendary creatures gain "tap to gain one mana of any color" not their land.
5.) sadly did not get any screenshots

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had Esika God of the Tree and other legendary Creatures
Wanted to produce mana in response to a board wipe by opponent (Farewell)
This wouldnt let me, even though creatures were untapped.
Tapped mana would have been used to break clue tokens.