By playing this card early in the game you have the opportunity to slam your creatures without fearing your opponent playing board wipes
Although this will not be a sideboard guide but more a how to play each matchup, I do have a short sideboard guide against most decks in Modern that you can find here
And there are probably +1/+1 counters and even more kinds of counters in the set
Tyranid Invasion is great early (since you usually have three opponents), Tyranid Prime is absolutely bonkers, one of the best cards in the deck, and Tyrant Guard is pretty good, offering protection to your board
Thanks to Contender's enter the battlefield trigger, we are able to select the best Knight, Aura, Equipment, or legendary artifact card from the top five of our deck and add it to our hand
To break through to the creature, youll have to complete a Saga first, and its far from the worst Saga to play