I thought I would be done with six parts, but during lunch I couldn’t help, but think about this one.
Generally green gets the cheapest creatures. Especially the bigger ones, but white does have some benefits in this regard. White also has fairly cheap creatures, but where white shines is cheap, big fliers, usually angels. However, in Khans of Tarkir, we have two pretty good ones, which could be good. Wingmate Roc has been getting some attention, but actually more interested in this one:
Who does he combo well with? How about Ajani Steadfast? Putting a +1/+1 counter on each of your creatures can make the Sentinels big very quickly. With some effective token producers (Elspeth, Brimaz, King of Oreskos, Herald of Anafenza) followed by Ajani’s minus can make Sentinels huge in one blow.
Since we can’t really draw extra cards, we should try to use our mana all the time. For this purpose (besides the Herald and the Sentinels), I’d use Avacyn, Guardian Angel, which is in itself very effective attacker and blocker, as well as Dauntless River Marshall, which is very strong for its cost as well, as long as we can get an Island on the table.