cards/CardFaxMachine.cs
using Sandbox;
using System.Threading.Tasks;

public class CardFaxMachine : Card
{
	public override bool ShouldHandleEvent( EventType eventType )
	{
		return eventType == EventType.Choose && Manager.Instance.ChosenCard == this && !(Manager.Instance.ChosenCards.Where(x => x.CardType == CardType.FaxMachine).Count() == 2);
	}

	public override async Task HandleEventAsync( EventType eventType )
	{
		var otherFaxMachines = Manager.Instance.Cards.Where(x => x.CardType == CardType.FaxMachine && x != this).ToList();
		if ( otherFaxMachines.Count == 0 )
			return;

		List<Card> cardsToShake = new();

		otherFaxMachines.Shuffle();
		cardsToShake.Add( otherFaxMachines.FirstOrDefault() );

		var otherCards = Manager.Instance.Cards.Where( x => x.CardType != CardType.FaxMachine ).ToList();
		otherCards.Shuffle();

		for ( int i = 0; i < Math.Min( 2, otherCards.Count ); i++ )
			cardsToShake.Add( otherCards[i] );

		cardsToShake.Shuffle();

		Manager.Instance.PushEventMessage( this, eventType );

		await Task.DelayRealtime( 50 );

		Manager.Instance.PlayCardSfx( "fax_machine", this, volume: 1.4f, pitch: Game.Random.Float( 0.98f, 1.02f ) );

		await Task.DelayRealtime( Game.Random.Int(550, 650) );

		foreach ( var card in cardsToShake )
		{
			await Manager.Instance.ShakeCard( card );

			await Task.DelayRealtime( 150 );
		}

		await Task.DelayRealtime( 250 );

		Manager.Instance.PopEventMessage();
	}
}