If a creature you control with power 4 or greater has menace, it can’t be blocked by only one creature and it can’t be blocked by more than one creature, so it simply can’t be blocked.
03-05-2019
wotc
Once a creature you control with power 3 or less has become blocked by two or more creatures, changing its power won’t cause either blocking creature to stop blocking it.
03-05-2019
wotc
Challenger Troll’s ability affects itself as long as its power remains 4 or greater.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.