Guilds of Ravnica

Chance for Glory | Instant | | Creatures you control gain indestructible. Take an extra turn after this one. At the beginning of that turn's end step, you lose the game. | Bram Sels

Deafening Clarion | Sorcery | | Choose one or both — • Deafening Clarion deals 3 damage to each creature. • Creatures you control gain lifelink until end of turn. | Adam Paquette

Skyknight Legionnaire | Creature | Human Knight | Flying, haste | Chase Stone

Tajic, Legion's Edge | Legendary Creature | Human Soldier | Haste Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) Prevent all noncombat damage that would be dealt to other creatures you control. {R}{W}: Tajic, Legion's Edge gains first strike until end of turn. | Anthony Palumbo

Boros Locket | Artifact | | {T}: Add {R} or {W}. {R/W}{R/W}{R/W}{R/W}, {T}, Sacrifice Boros Locket: Draw two cards. | Aaron Miller