MTG Mono White Aggro Deck by SimpleCat

At the beginning of combat on your turn, if you control three or more creatures, this creature gets +1/+1 until end of turn and you gain 1 life.

Whenever you gain life, put a +1/+1 counter on this creature.

Lifelink Whenever this creature attacks while saddled, search your library for a basic Plains card, reveal it, put it into your hand, then shuffle. Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Whenever another creature you control enters, put a +1/+1 counter on this creature. As long as this creature has three or more +1/+1 counters on it, it has flying and is a Knight in addition to its other types.

Flying

Other Cats you control get +1/+1. Whenever Arahbo or another nontoken Cat you control enters, create a 1/1 white Cat creature token.

Vigilance (Attacking doesn't cause this creature to tap.) When this creature enters, create a 1/1 white Cat creature token.

Lifelink (Damage dealt by this creature also causes you to gain that much life.) When this creature enters, put a +1/+1 counter on each of up to two other target creatures you control.

Creatures your opponents control enter tapped. Whenever a creature an opponent controls enters, you gain 1 life.

Enchant basic land you control When this Aura enters, exile target creature or planeswalker an opponent controls until this Aura leaves the battlefield.

When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.

Destroy all creatures.

Return all creature cards with mana value 2 or less from your graveyard to the battlefield.

Exile all creatures. Incubate X, where X is the number of creatures exiled this way. (Create an Incubator token with X +1/+1 counters on it and "{2}: Transform this token." It transforms into a 0/0 Phyrexian artifact creature.)

({T}: Add {W}.)