Board Thread:Versus Battles/@comment-24900075-20180709020410/@comment-24900075-20180709025506

"Final Fantasy XIII Edit

Arise is a spell automatically cast by Eidolons when their summoner's HP reaches zero or when the Eidolon's SP reaches zero and the summoner's Gestalt gauge is depleted. It revives the party leader with full HP but the Eidolon is instantly dismissed.

Lightning Returns: Final Fantasy XIII Edit
Arise appears as an EP ability that revives Lightning to full health after being defeated in battle and costs 2 EP (easy mode) or 3 EP (normal/hard mode) to use. It can still be cast when the current EP is already fewer than the EP required, even 0.1 EP, but the health will be restored according to the EP used."

Both versions of Arise are limited. The first version is only effective once and the 2nd version drains EP, which would be a drain on Lightning's spells. If she uses all her EP, whether by continuially revivng or using spells, she's done.