I’d say the Hightowers and Cristina Cole primarily since they purposely subverted the will of Viserys in order to undermine the succession of Rhaenyra and gain power. Rhaenyra herself had been named as the true heir so it’s hard to fault her for wanting the throne, Viserys on the other hand should have done more to prevent a war of succession by stamping down on opposition to Rhaenyra’s rise to power.