This secret technique allows the Red Mage to cast off restrictions and instantly invoke magic spells. They can inundate the enemy with elemental magic, or turn the tides of battle with healing and enhancing spells. Use it when you need instantaneous casting power.
While active, all spells cast will have zero cast time other than the casting animation. This applies even for spells that aren't normally associated with Red Mage, such as Ninjutsu, if utilizing a Ninjasubjob. However, spells still cannot be cast non-stop like Job Abilities can; there is still an approximate 2.5 - 3 second delay after casting a spell that you must wait before you're able to start casting another one, and Chainspell still does not remove this delay.
All spells cast while this ability is active will have their recast timers reduced to zero as well, meaning that the same spell could be immediately cast again if so desired and if MP permits (following the 2.5 - 3 second delay). However, note that the activation of this ability does not cause any spells that were already recharging to immediately become available. In other words, if you intend to use spells like Raise or Drain (spells with long recast times) during Chainspell, make sure they are ready to be cast prior to engaging Chainspell.
MP costs of spells used while under Chainspell's effect are not reduced or affected in any other way. Due to the likely high amounts of spells cast in a short period of time, it would be wise to ensure that you have sufficient MP to cast everything that you intend to cast prior to engaging the ability.
Very effective when combined with proper timing of the ability Convert. Convert will greatly extend your effective MP "pool" (MP Limit) allowing for more spells to be fired under Chainspell's duration.
Chainspell will not prevent spells from being interrupted due to movement; it is still necessary to stand relatively still in order to cast as with normal magic casting. However, short of enemy attacks that cause knockback, it will be difficult for any enemy to interrupt your casting while Chainspell is active. Depending on the enemy, you may wish to have some sort of safeguard against attacks that cause sleep or other debilitating status effects.
The rate at which you can cast consecutive spells is also hindered slightly by the previous spell's animation. Generally it is possible to cast an instant spell every one to two seconds (About 15 casts if you don't have to convert i.e. Wizard's Drink + full MP in Besieged.)
Uses for Chainspell
Unlike most other 1-Hour abilities which usually have one set purpose (usually to inflict greater damage, or to prevent/heal it), Chainspell has numerous potential uses due to the utilitarian nature of a Red Mage's arsenal of spells (an arsenal that only grows if certain subjobs are used). The list of uses grows as the Red Mage's spell list grows. Some of the more common uses include:
Blink/Stoneskin. Defensive spells which, under normal circumstances, have cast/recast times that are too long to be very effective by themselves against tough opponents. However, with Chainspell active, they can be repeatedly cast and form an effective barrier for a relatively small MP cost (compared to Cures).
If Ninja is used as the subjob, Blink may be replaced with Utsusemi. In return, you get a better defensive spell that costs no MP.
Sleep/Bind/Gravity. These spells are capable of keeping several enemies under control, but all have high recast times. If a situation gets particularly crowded and hectic, Chainspell can help you regain control.
"Zerg" tactics. Ensure that your MP is full and Convert is ready, then use Chainspell and fire away with your strongest appropriate elemental nukes. This will expend all of your MP or at least a great deal of it, but will allow you to inflict a great deal of damage on certain enemies in a short deal of time, possibly even exceeding that which can be achieved by other conventional "damage dealer" jobs within that same window of time. This tactic is commonly used in BCNMs or other Battlefields where the goal may be to defeat something as quickly as possible. One such case is when fighting the Snoll Tzar.
Drain/Aspir. These spells can be very potent but are normally restricted by their high recast times. Chainspell negates them, allowing one or both of these spells to be spammed continuously. These spells can be made even more effective by utilizing Dark Arts from a Scholar subjob in order to enhance Dark Magic skill. In some cases, Chainspell-Drain may be preferred for damage purposes instead of Chainspelling an elemental nuke, due to Drain being much more forgiving on the MP cost. It usually will not match the damage that your strongest elemental nukes can do, however.
Warp/Escape/Teleport. Spells with normally long casting times can be used instantly while under Chainspell's effect, in order to quickly escape a dangerous situation. These require certain subjobs; make sure you have the appropriate one beforehand.
Stun. Against dangerous enemies or Notorious Monsters, repeated Stuns may be what you need in order to prevent their devastating attacks. This technique is employed often in various high-level activities and is commonly referred to as Chainspell-Stun, or CSS. Be aware that repeated Stuns accrue a very high amount of enmity, so by the time Chainspell ends, if the enemy isn't already defeated, the Red Mage may find himself with hate, depending on situation.
Cure Bomb. Preferable after a Paladin has used Invincible, easy way to get the party back to normal status. Watch out for the hate!
/ja Chainspell <me>
Since Chainspell is a one hour special, some people prefer not to make a macro for it to prevent unintentional activation.