While playing Fortnite, all players will have what is called a Collection Book. This book is meant to be fill with cards, the same you receive by retiring heroes and recycling Weapons. It's key to add items to you Collection Book, because, as you do, your Collection Book will continue to Level Up. Each and every time you level up your Collection Book, you will be gifted with highly useful Rewards, some of which, like Pure Drops of Rain, Lighting In A Bottle and Training Manuals, are used to help Evolve your characters.
All Collection Book Rewards
Level 2 - 500 Hero XP
Level 3 - Uncommon Schematic
Level 4 - 500 Survivor XP
Level 5 - 6 Pure Drops of Rain
Level 6 - 500 V-Bucks
Level 7 - 7 Pure Drops of Rain
Level 8 - Uncommon Constructor and Survivor
Level 9 - 1 Skill Point
Level 10 - 500 Schematic XP
Level 11 - 8 Pure Drops of Rain
Level 12 - Choice of Uncommon Melee Weapon or Shotgun
Level 13 - Golden Llama
Level 14 - 100 Hero XP
Level 15 - 3 Training Manuals
Level 16 - Rare Ranged Weapon
Level 17 - 9 Pure Drops of Rain
Level 18 - 2 Skill Points
Level 19 - 1000 Survivor XP
Level 20 - 10 Pure Drop of Rain, 5 Lightning in a Bottle
Level 21 - XP Candy Pack
Level 22 - 3 Training Manuals
Level 23 - Rare Ninja or Outlander
Level 24 - Uncommon and Rare Survivors
Level 25 - Epic Survivor
Level 26 - 500 V-Bucks
Level 27 - 10 Pure Drops of Rain
Level 28 - Rare Trap
Level 29 - 5 Lightning in a Bottle
Level 30 - 100 Schematic XP
Level 31 - Trap Pack
Level 32 - Rare Survivors
Level 33 - 2 Skill Points
Level 34 - 12 Pure Drops of Rain, 5 Lightning in a Bottle
Level 35 - 1200 Hero XP
Level 36 - 8 Training Manuals
Level 37 - 1200 Survivor XP
Level 38 - Rare Hero and Survivors
Level 39 - 1200 Schematic XP
Level 40 - Rare Survivor
Level 41 - Weapon Pack
Level 42 - 3 Eyes
Level 43 - 8 Training Manuals
Level 44 - 1500 Hero XP
Level 45 - Epic Survivor
Level 46 - 2 SKill Points
Level 47 - 14 Pure Drops of Rain, 5 Lightning in a Bottle, 1 Eyes
Level 48 - 1500 Hero XP
Level 49 - Epic and Rare Survivors
Level 50 - 1500 Schematic XP
Level 51 - Choice of Rare Hero
Level 52 - 5 Lightning in a Bottle, 2 Eyes
Level 53 - 4 Training Manuals
Level 54 - Trap Pack
Level 55 - 2000 Hero XP
Level 56 - 2 Skill Points
Level 57 - Rare Weapon
Level 58 - 2000 Survivor XP
Level 59 - 2000 Schematic XP
Level 60 - 5 Lightning in a Bottle, 1 Eye
Level 61 - Trap Pack
Level 62 - Uncommon Schematic, 2 uncommon Traps
Level 63 - 4 Training Manuals
Level 64 - XP Candy Pack
Level 65 - Epic and Rare Survivors
Level 66 - 3 Skill Points
Level 67 - 16 Pure Drops of Rain, 5 Lightning in a Bottle, 2 Eyes
Level 68 - 2000 Hero XP
Level 69 - 3 Skill Points
Level 70 - 18 Pure Drops of Rain, 5 Lightning in a Bottle, 3 Eyes
Level 71 - Weapon Pack
Level 72 - 2000 Survivor XP
Level 73 - Epic and Rare Survivors
Level 74 - 10 Training Manuals
Level 75 - 20 Pure Drops of Rain, 10 Lightning in a Bottle, 4 Eyes
Level 76 - 2000 Schematic XP
Level 77 - 3 Skill Points
Level 78 - 3000 Hero XP
Level 79 - Epic and Uncommon Survivors
Level 80 - 3000 Survivor XP
Level 81 - Epic Trap Pack
Level 82 - 2 Epic Survivors, 1 Epic Hero
Level 83 - 10 Lightning in a Bottle, 4 Eyes
Level 84 - 3 Skill Points
Level 85 - 3000 Schematic XP
Level 86 - 1 Epic Survivor, 2 Rare Survivors
Level 87 - Choice of Epic Hero
Level 88 - 22 Pure Drops of Rain, 10 Lightning in a Bottle, 5 Eyes
Level 89 - 3000 Hero XP
Level 90 - 3000 Survivor XP
Level 91 - 500 V-Bucks
Level 92 - 3000 Schematic XP
Level 93 - Rare Schematic
Level 94 - 4 Training Manuals
Level 95 - XP Candy Pack
Level 96 - Uncommon Defender
Level 97 - Epic and Rare Survivors
Level 98 - 3 Skill Points
Level 99 - 4000 Hero XP
Level 100 - Epic Schematic