I'm glad you asked the question online as it was ambiguous
I also researched the matter and the proper ruling to quote here would be :
702.25b If a permanent phases out, its status changes to “phased out.” Except for rules and effects that specifically mention phased-out permanents, a phased-out permanent is treated as though it does not exist. It can’t affect or be affected by anything else in the game. A permanent that phases out is removed from combat. (See rule 506.4.)
Example: You control three creatures, one of which is phased out. You cast a spell that says “Draw a card for each creature you control.” You draw two cards.
Example: You control a phased-out creature. You cast a spell that says “Destroy all creatures.” The phased-out creature is not destroyed.
I have been playing Derevi since its release but I have yet to test a full tax list.
I usually finish games with a lot of flying creatures + true conviction ( high casting cost but double derevi's triggers.) Usually tutored with Academy Rector
I also love abusing the latest combat ruling with reconnaissance. You should definitively give it a try as it allow you to swing with all creatures, remove from combat those you are about to lose, then remove from combat those who dealt damage to your opponent after they dealt their damage.
Then you use your Derevi's triggers to tap opponents land or untap your blue mana source in order to pay for stasis upkeep. One of my favorite card in Derevi.
I also researched the matter and the proper ruling to quote here would be :
So I should not have been able to gain control of the scalelord reckoner as I was no longer controlling the helm of possession.
it will either give you the game with living plane or kill your deck.
I took it out personally as I lost several game to it.
Otherwise, it look good.
When reconnaissance was printed, yes.
But since they changed the combat ruling, the creatures are still considered attacking even after they did their combat damage.
The same strategy is used in Legacy with Maze of Ith. Swing with a creature then untap it after damage is done to have a blocker.
I usually finish games with a lot of flying creatures + true conviction ( high casting cost but double derevi's triggers.) Usually tutored with Academy Rector
I also love abusing the latest combat ruling with reconnaissance. You should definitively give it a try as it allow you to swing with all creatures, remove from combat those you are about to lose, then remove from combat those who dealt damage to your opponent after they dealt their damage.
Then you use your Derevi's triggers to tap opponents land or untap your blue mana source in order to pay for stasis upkeep. One of my favorite card in Derevi.