Have any of you considered Drop of Honey in U/G Colossus Orchard/Oath?
Drop of Honey

Enchantment
At the beginning of your upkeep, destroy target creature with the least power. It can't be regenerated. (If two or more creatures are tied for least power, target any one of them.)
When there are no creatures in play, sacrifice Drop of Honey.
It seems to have the following advantages:
(1) Hoses Goblin Welder, Platinum Angel, and other problematic creatures.
(2) Buys time until you can find Oath.
(3) Good synergy with Orchard:
(a) Cleans up extra Spirit tokens.
(b) Orchard can keep the Drop around abitrarily long (barring wasteland).
[/list:u](4) Plays nicely with indestructibility and large power of Colossus.
[/list:u]
I haven't had a chance to test these idea, but I expect Stax and Storm combo to be rough matchups. It's not clear how Drop of Honey helps in those matchups.