I made little deck which mainly runs around Willbreaker. Deck is full of stuff that can trigger Willbreakers ability and also stuff that try to get Willbreaker on board. Haven't lost single match yet so don't really know what actually is bad match for this build.
Some random matches in youtube video with this deck
https://www.youtube.com/watch?v=pMoM9TATj6IDeck list
3 x
Sigiled Starfish4 x
Gatecreeper Vine2 x
Evolutionary Leap4 x
Nissa's Pilgrimage1 x
Jace, Vryn's Prodigy1 x
Nissa, Vastwood Seer1 x
Kiora, Master of the Depths3 x
Reclamation Sage4 x
Wildsize3 x
Whirler Rogue2 x
Scatter to the Winds3 x
Bounding Krasis1 x
Greenwarden of Murasa2 x
Willbreaker2 x
Guardian of Tazeem1 x
Part the Waterveil9 x
Forest6 x
Island2 x
Lumbering Falls2 x
Hinterland Harbor4 x
Simic GuildgateCard explanation:
Sigiled Starfish - To get the deck running. Main goal is to find Evolutionary Leap or Willbreaker. Also helps to block early aggro, fix mana etc.
Gatecreeper - Mana fixer, early blocker and food for leap.
Evolutionary Leap - Engine of the deck. Keep in mind that u can sac Willbreaked creatures so opponen wont get them back even if Willbreaker is killed.
Nissas's Pilgrimage - Booster for 5 mana drops and also land thinner.
Reclamation Sage - For taking out important enchantments or artifacts.
Jace - Need i say anything
. Well first ability is amazing with Willbreaker
Nissa - Again pretty clear why it's in the deck.
Kiora - Great abilities for this build. First ability also synnergies with Willbreaker and second "tutors" Willbreaker.
Wildsize - Surprise combat trick (this card is almost nonplayed and opponent wont suspect it) and also trigger for Willbreaker.
Whirler Rogue - Great drop for 4 mana. Triggers Willbreaker. Creates 3 blockers for situation with heavy aggro.
Scatter to the Winds - Only counter in deck. For important spells like Ulamog.
Bounding Krasis - Surprise blocker and also trigger Willbreaker
Greenwarden of Murasa - Great card alone (even with the bug). Can bring back important cards like Leap, Walkers or Willbreaker.
Willbreaker - Decks main idea. Spam stuff and control all creatures.
Guardian of Tazeem - Trigger Willbreaker. Great 5 mana flyer. Can block most of the stuff and also clear out creatures with tapping.
Part the Waterveil - Mainly for Planes Walkers to gain extra turn for their abilities.