Crystal Invoke

This feature is the powered up version of Friendship Invoke. There are two methods of Crystal Invocation.
 * Single Invoke costs 5 crystals and invokes one spirit randomly.
 * Mega-Invoke costs 50 crystals. It is equivalent to doing ten single invokes except you are guaranteed one A Rank Spirit.

Events frequently modify Crystal Invocation such as adding limited edition Spirits, increasing chances of A Ranks, or allowing for re-invocation/redo. It's best to save your crystals until one of these events.

Is the Spirit That I Invoked Any Good?
Pretty much any A Ranked Spirit has some merit. There is a lot of debate over the dominance of one over the other. Some of the non A Ranks are considered at least usable. The following table gives a rough guide. If you disagree with any of the ratings, take it to the Spirit Ranking Project board.
 * ★ - Sorry, please try again
 * ★★ - If you're seriously strapped for anything better
 * ★★★ - Good enough for developing players. A few of the particularly disliked A ranks are demoted to this rating.
 * ★★★★ - Anyone not buying lots of crystals should keep um!

Deciding who is the best depends on your play style, what you're doing, and what cards you already have. Spirits with lower stats usually have better abilities. Healing skills are absolutely essential for boss battles. Heavy attack Spirits are better for tournaments. Quick charging special skills are preferable for tournaments too. Answer elimination is good for Tree quests with their difficult tri-color questions and if you're not so good at answering questions. You'll want one category changer on any team but more than one is undesirable. Absorb health, self heal, and attack all skills are considered the least useful. DC is not a good indicator of worth and in some cases is a major point against them.

Event exclusive spirits vary a lot and tend to have unique skills. You probably want to keep these just for the sake of novelty.

Unlimited Spirits
This table shows the spirits available and a comparison of their final forms.

A number of A rank Spirits were removed on April 22, 2014. The old list is preserved below.

S Ranks
Some non-exclusive Spirits have their S rank versions in the invoke pool. These are very rare.

Invoke Event Log
These Spirits or changes to the invoke mechanics were only available for a limited time. (A day/month/year format is used)