UW Control Control decks are generally good matchups for Mono-White even though were not particularly teched out for them, because theyre so clunky and we have Thalia, Archon, and Spellbinder to tax them
Pikachu ex has a special ability called Resolute Heart that sees that, if it has full HP and were to be Knocked Out by damage from an attack, it would not be Knocked Out and remain on the field with 10 HP instead
Swords that give their creatures protection from your whole deck, equipment that turns Planeswalkers into creatures, Umezawa's still-playable Jitte - there is a lot of annoying equipment out there
Weve also got the Generation Duel event, and the Yu-Gi-Oh
You declare attackers and turn Rakshasa Deathdealer sideways to tap it.Lets say youve got a [11] Rakshasa Deathdealers regenerate ability costs one black and one green mana