Cynet

Description
Cynet applies Link to all enemies for 3 seconds, causing them to take damage whenever any other target takes damage for the duration.

Strategy and Synergy
This card is obviously helpful in decks that can dish out a bunch of damage within a 3-second time window, such as Shield Throw decks or Poison decks (when timed smartly).

Like most other Calamity spells, you will likely need extra max Mana for this card to ever be helpful. If you have 3 max Mana when you play this card, you'll have to wait for your Mana to recharge before being able to cast spells (unless they cost 0). For this reason, Mana-supporting upgrades on this card are a must if you're low on max Mana.

Some enemies with multi-grid movement (i.e. Firechild, Spearper) have a small chance to avoid the Link by moving when Cynet is cast. As the situation is extremely rare, it may only be a 1~2 frame window or involve other conditions, like casting several spells in quick succession.

Cynet can serve as redundancy or replacement for Soul Link against Shopkeeper (Boss) to turn their Ice Walls Trap attack back against her. She will strike a 3x3 area for massive damage - that damage then being duplicated on her for each target struck. It has a shorter duration than Soul Link, but can apply the effect more consistently since you can cast it from anywhere on the board.