This Jolteon is pretty basic sweeper.

It's fast, and powerful enough to mostly one hit Pokemon who are weak to Thunderbolt/Shadow Ball, and can do decent damage to Pokemon that are not.

Whenever Jolteon is in danger, depending on if it has enough HP it can create a Substitute to take the hit, and with abit of luck it is possible to switch in another Pokemon safety into the Battle through Baton Pass.

Pulling this off effectively however requires great prediction of non damage dealing move's (Sword Dance for example.)
 