This deck looks cool. Whenever I see an
Oketra's monument, I always want to recommend
Whitemane Lion. The Lion is a decent card anyway, can be used to save someone important creature in a pinch or re-trigger an ETB effect, but it absolutely shines with the monument. Because of the
flash, it basically turns into "Pay W: create a 1/1 with
vigilance" at instant speed! You can just pump all your remaining white mana into tokens before your turn starts. An amazing budget mana sink in white. And if you have a skull clamp kicking around, the card draw is real. Also combo's great with
soul warden for two instances of life gain.
I mean, I'm not sure what you'd want to cut for it because like I say, the list looks pretty sweet, but as someone who has used and abused this combo and seen how out of hand it can get, I thought I'd share in case it interested you.