Trample only applies to creatures attacking the defending player or planeswalker
Even the animes logic of only four existing in the world helps elevate the cards status, even if in the real world there are countless copies
Fortunately for you and unfortunately for your opponents, because Blightsteel Colossus is indestructible, if they dont have an exile card, a creature 11 power or greater, or a horde of creature tokens with a total power of exactly 11, the game is done
Full Art/Rayquaza GX 2019 Yellow A Hidden Fates Premium Collection-Jumbo (#177a) This jumbo card is particularly unique and fetched $121.50
I wouldnt advise entering a Legacy Open with the deck as is though
For six mana, you can exile another Creature and put a +1/+1 counter on it