Each character has unique abilities in Horde Mode. This How To Use JD Artillery Strike In Gears 5 explains one such ability, the devastatingly powerful Artillery Strike usable only by JD. This is the default ability on the character. You do not need to unlock it or equip it, it’s JD’s Ultimate Ability.
In the Horde Menu JD’s Ultimate Ability reads as follows. Drops five artillery rounds on an enemy in the open, that is marked by JD. Sounds simple enough right? Well, it is, if you have already made yourself familiar with the mark ability otherwise it’s near impossible.
How To Use JD Artillery Strike In Gears 5
The first part you need to pay attention to is “in the open”. This ability will not work if the enemy is inside a builder or another interior without direct view of the sky, as the drop comes from above. If your enemy is still in the open and pressing Y does not launch his Ultimate Ability, it’s because you have yet to mark the target.
The default setting for marking a target is to aim directly at the target, so they are the focus of your reticle,then press in the left stick. That will mark the target. You can then simply press Y to launch JD’s Artillery Strike.
from GamersHeroes http://www.gamersheroes.com/game-guides/how-to-use-jd-artillery-strike-in-gears-5/