Xylemic Reroute1U
Sorcery
In addition to cast ~, sacrifice a Forest.
Move any number of +1/+1 counters from any number of creatures to target creature.
Fealty Dragon1RRWU
Creature - Dragon
Flying, Vigilance
As long as you own ~, it has haste.
At the beginning of each player's upkeep, that player may pay 5. If he or she does, he or she gains control of ~.
5/5
Drying Farmland
Land (R)
~ enters the battlefield with 2 farm counters.
Whenever you cast a spell or activate an ability that isn't a mana ability, remove a farm counter from ~. t: Add 1 to your mana pool. If ~ has any farm counters on it, instead add one mana of any color to your mana pool.
Intermediary ReformationWWUBB
Sorcery
In addition to cast ~, exile a creature card from your graveyard.
Return target creature card from a graveyard to the battlefield under your control. That creature has "t, Exile this creature: Return target creature card from a graveyard to the battlefield under your control."
Unyielding Steel2
Artifact - Equipment
As long as ~ is not equipped to a creature, it is indestructible.
Equipped creature gets +2/+0 and has vigilance.
Equip (2/W)(2/W)
Opaque Sermon2WB
Sorcery
Count the number of creatures with converted mana cost 1 or less on the battlefield. You gain life equal to twice that number, then target opponent loses life equal to that number.
Caldera Elder1(U/R)(U/R)
Creature - Treefolk t: ~ gets +0/+2 until end of turn. Activate this ability no more than twice each turn. (U/R),q: Switch ~'s power and toughness until end of turn.
1/3
Contagious CallingB
Sorcery
Choose one or both—Return target creature card with infect from your graveyard to your hand; and/or, return target card named Contagious Calling from your graveyard to your hand and you gain a poison counter.
Entwine 1
Last Trek1WB
Instant
Exile target creature. At the beginning of the next end step, return that card to the battlefield under its owner's control, then destroy it. It can't be regenerated.
Verdant Sprawl1G
Enchantment - Aura
Enchant nonbasic land
Whenever enchanted land becomes tapped, put a 1/1 green Saproling creature token onto the battlefield under your control.
I can't speak for the Avenger because I don't run any, but I've consistently used a late game Young Wolf to flip Garruk or to sacrifice it for flipped Garruk's -1 ability, tutoring a finishing Elder.
Sorcery
In addition to cast ~, sacrifice a Forest.
Move any number of +1/+1 counters from any number of creatures to target creature.
Creature - Dragon
Flying, Vigilance
As long as you own ~, it has haste.
At the beginning of each player's upkeep, that player may pay 5. If he or she does, he or she gains control of ~.
5/5
Creature - Eye Knight
Defender
As long as you control no nonwhite creatures, ~ loses defender and gains intimidate and vigilance
2/5
Land (R)
~ enters the battlefield with 2 farm counters.
Whenever you cast a spell or activate an ability that isn't a mana ability, remove a farm counter from ~.
t: Add 1 to your mana pool. If ~ has any farm counters on it, instead add one mana of any color to your mana pool.
Intermediary Reformation WWUBB
Sorcery
In addition to cast ~, exile a creature card from your graveyard.
Return target creature card from a graveyard to the battlefield under your control. That creature has "t, Exile this creature: Return target creature card from a graveyard to the battlefield under your control."
next; WBR
Artifact - Equipment
As long as ~ is not equipped to a creature, it is indestructible.
Equipped creature gets +2/+0 and has vigilance.
Equip (2/W)(2/W)
Sorcery
Count the number of creatures with converted mana cost 1 or less on the battlefield. You gain life equal to twice that number, then target opponent loses life equal to that number.
Creature - Treefolk
t: ~ gets +0/+2 until end of turn. Activate this ability no more than twice each turn.
(U/R),q: Switch ~'s power and toughness until end of turn.
1/3
next; G vampire
Sorcery
Choose one or both—Return target creature card with infect from your graveyard to your hand; and/or, return target card named Contagious Calling from your graveyard to your hand and you gain a poison counter.
Entwine 1
Creature - Dryad
Forestwalk
Sacrifice ~: Soldier creatures you control gain forestwalk until end of turn.
1/1
Instant
Exile target creature. At the beginning of the next end step, return that card to the battlefield under its owner's control, then destroy it. It can't be regenerated.
Next: Thoughtslice
Enchantment - Aura
Enchant nonbasic land
Whenever enchanted land becomes tapped, put a 1/1 green Saproling creature token onto the battlefield under your control.