Meren of Clan Nel Toth [Commander Masters] Sphinx Wizard Its activated abilities can't be

Its activated abilities can't be activated unless they're mana abilities

"Have you ever seen a world fall to its knees

Set: Commander Legends Tokens Type: Token Creature — Dragon Rarity: Common Flying

Set: Secret Lair Drop Series Type: Legendary Creature — Angel Rarity: Mythic Cost: {5}{R}{R}{R} This spell can't be countered

the card with the higher toughness wins and remains face up

Meren of Clan Nel Toth [Commander Masters] Sphinx Wizard Its activated abilities can't beSet: Commander Masters Type: Legendary Creature Human Shaman Rarity: Rare Cost: {2}{B}{G} Whenever another creature you control dies, you get an experience counter. At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.