In a deck that can go wide on the board, as Knights certainly can, this ability is incredibly dangerous, and can easily finish an opponent off in conjunction with other board-buff effects such as History of Benalia
We live in a timeline where in Magic we have Sabin Suplexing The One Ring
(2023-02-04) Toxic doesn't change the amount of combat damage a creature deals
For 2 mana and a further 2 equip cost, it does nothing (not even a token stat boost) but generate counters when the creature its on deals damage via battle
Legendary Enchantment Delirium If a source you control would deal noncombat damage to a permanent or player while there are four or more card types among cards in your graveyard, it deals double that damage instead
This blog is all about hitting land drops, so giving your opponent one is not what I am interested in