In terms of what the decks do, the Tyranid Swarm deck focuses on building a massive army with adaptable creatures and counters, though it falls slightly short in power compared to the other decks
These would likely utilize aggressive ground creatures such as Topan Freeblade and Jhessian Thief and behave similarly to the Green/White Renown archetype
The main reason is that it is one of the best searchers for pendulum monsters in the game, and their primary normal summon
Supported by cheap cantrips, burn spells, and efficient threats like Thing in the Ice, it can apply immense pressure early in the game
Note that this will work on your skulk stuff too, so you can toss those in here too
Legality depends on the tournament format -- Channel Lightning Valley can be legal in some formats and banned or restricted in others