Energy can refer to the resource needed to start missions (or battles) in the Campaign mode (except for the "Tank" and "Elemental Spirit Asylum" missions) or to the Energy Bar below all Heroes and Titans during Battles.
Energy for the Campaign 
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The Energy regenerates by 1 each 6 minutes up to the max Energy refill limit (Energy Cap) determined by the Team Level. Additionally, players can receive 3 times 60 Energy in the Daily Quests (with a 1-hour cooldown between this quests) for 180 free Energy per day.
Free Energy can also be gained by leveling up the Team Level or by receiving Gifts, most Gifts can be stored for an unlimited time in the Mail (if desired).
Even more Energy can be bought with Emeralds directly, by clicking on the Energy value, or as Bottled Energy in the Town Shop. The cost for the first option increases if used multiple times and resets at the end of the player's Game Day.
Comparison of all possible options, sorted by the Energy per Emeralds ratio:
| Source | Energy | Emeralds | Ratio |
|---|---|---|---|
| Purchase 1−2 | 120 | 50 | 2.4 |
| Purchase 3−7 | 120 | 100 | 1.2 |
| Purchase 8−13 | 120 | 150 | 0.8 |
| Bottled Energy | 200 | 300 | 0.67 |
| Purchase 14+ | 120 | 200 | 0.6 |
Many of the (monthly) Seasons (e.g. Ascension Season) provide an "Energy Recovery x3" feature for a fixed number of days (Gold Ticket required). This means that a player will gain 3 units of Energy every 6 minutes, rather than 1. This also lifts the Energy Cap +50. For example, if a player reached level-100, they could have an Energy Cap of 60 + level = 160, plus an extra 50, giving a total Energy Cap of 210.
Energy in Battles[]
The Energy in Battles is used to activate the ultimate/white skill of most Heroes (with some exceptions) and Titans. The Energy is gained by attacking, using skills, taking damage, or killing opponents:
The Energy is displayed as a yellow bar right under the (green) health bar of Heroes and Titans. If it is fully charged the border of their icons ignites and keeps "burning" until activated. Activating the ultimate/white skill depletes the bar to 0%.
The Energy bar caps at 100% for Heroes, Titans, and Elemental Spirits (Totems). Elemental Spirits receive the same Energy as the Titans of their element, but cap at 3,000 Energy.
| Type | Heroes | Titans |
|---|---|---|
| Basic attack and skills | 10% (100 Energy) | 20% (200 Energy) |
| Losing 1% health or dodging* | 1% (10 Energy) | 0.5% (5 Energy) |
| Killing blows | 30% (300 Energy) | 30% (300 Energy) |
* A successful dodge grants the Energy equal to the potentially lost Health
Exceptions[]
Celeste: She only needs 50% of Energy to activate "Two Fates", which will change her into Dark or Light form. Since Celeste only needs half of the Energy to "ult" than other Heroes, her ultimate skill/s only last 4.5 seconds (instead of 9). See Celeste's page for more info.
Astrid & Lucas: They have another system similar to Energy, which is called Rage, with a red bar (instead of yellow). Each basic attack done by Astrid charges Rage up be 17%. Once Rage reaches 100%, her pet transforms into rage form, rushing to the front line and taking the enemy's attacks on itself. It takes no damage from these attacks, but each attack deprives the pet of 7% rage. While fueled by rage, the pet attacks the nearest opponent. Once its rage runs out, the pet will revert to its passive form (next to Astrid). See Astrid and Lucas' page for more info.
Isaac: Similar to Energy and Rage, he uses Charge. Each basic attack charges up by 10%. When the Charge reaches 100%, Isaac can activate Tes'Lin's Overdrive. See Isaac's page for more info.
Pets[]
The Pets' Energy is also displayed by a yellow bar, however, since Pets do not have a Health Bar, their Energy Bar is directly under their icon. Unlike Heroes and Titans, they gain their Energy gradually for a duration of 15 seconds. Then the border of their icons ignites and keeps "burning" until it is activated as well. The Energy Bar starts loading again right after the activation of their white skill thus a Pet can "ult" a maximum amount of 8 times during a regular 2-minute Battle (on "Auto" mode).
Videos[]
Videos explaining the mechanic with several examples:
