It is my understanding that you want to plot two graphs in one figure. You tried hold on but it didn't work.
It is not clear whether you want both plots in the same graph, or both plots in separate graphs but in the same window. Below are the possible solutions for either of those which you can try. I've taken dead nodes v/s rounds and alive nodes v/s rounds for the plots.
1) hold on, hold off – both dead and alive nodes in the same plot, same figure
title('Nodes vs Rounds')
legend('Dead Nodes','Live Nodes','Location','best');
2) subplot – dead nodes and alive nodes in two separate plots, but in the same figure
title('Dead Nodes vs Rounds')
ylabel 'Dead Nodes';
title('Live Nodes vs Rounds')
ylabel 'Live Nodes';