Persistent, as defined by good 'ole Merriam-Webster, (This is copy pasted right from their website)
Main Entry: per·sis·tent
Pronunciation: \-tənt\ Function:
adjective Etymology: Latin
persistent-, persistens, present participle of
persistere Date: 1826
1
: existing for a long or longer than usual time or continuously: as
a
: retained beyond the usual period <a
persistent leaf>
b
: continuing without change in function or structure <
persistent gills>
c
: effective in the open for an appreciable time usually through slow volatilizing <mustard gas is
persistent>
d
: degraded only slowly by the environment <
persistent pesticides>
e
: remaining infective for a relatively long time in a vector after an initial period of incubation <
persistent viruses>
The name couldn't BE more perfect. The first definition is that it EXISTS FOR A LONG OR LONGER THAN USUAL TIME OR CONTINUOUSLY. How is that not EXACTLY what this ability does?
Also, for the people who seem confused as to what Persistent does, I'll post it again for this page.
Persistent
When the Pokemon with this ability uses any of the following moves: Trick Room/Gravity/Tailwind/Heal Block/Safeguard, their duration is increased by 2 turns.
Basically, you still have to USE the move, this isn't auto set up... It doesn't stack. Trick Room/Gravity/Heal Block/Safeguard get bumped up to seven turns, and Tailwind gets bumped up to the standard 5.
I'm not for giving Tailwind anything more than the standard +2 boost, because I think Time Mage said it earlier, Tailwind is beneficial to EVERY pokemon in the game and seems like a splashable move on this thing. (Just throw it on the pokemon, and it'll help any team out) where as something like Gravity/Trick Room need dedicated teams.