i forgot to mention that siege rhyno is 3 colours, also it seems like a control deck, which is why I thought
vigilance would be better, siege rhyno may have an initial effect, but you are trying to win over time so what it does on the boardis more important(and while it is one of the best 4 drops for stats it doesn't win you the game the way you would want a control deck card to).... I should have said one avacyn, gardian of hope because that can end the game by itself when played(even if you do not have the permanents for its secondary effect) then there is
deathbringer liege(adds control utility to your non-creature spells), then there is
desecration demon(a 6/6 that gets your opponent to sac creatures if they want to stay safe - and this is in a control deck, where them doing so will help you a lot in the long run) eidolon of rhetorich COULD help you(though not as much as in a counter deck) then there is
hundred handed one(4 mana 3/5 with
vigilance and an awesome monstrous ability that you will probably get to concidering this deck is control)