Chandelure is an amazing wall, and a great hitter. You may be thinking, WTF is this guy thinking? Chandelure, ordinarily, is horribly frail, and rather slow. The only real benefit is its base 145 Sp. Atk, the highest non-legendary BST. With Shadow Tag, it becomes an amazing trapper, and can use it to it's advantage with a very simple moveset:
Timid/Modest, 252 Spd, 252 Sp. Atk, 6 HP
Shadow Ball / Taunt
It functions as both a wall with defenses over 800 (@+6), and as an amazing, but rather slow sweeper with a Sp. Atk, at +6, of over 1500 (w/Modest). With Shadow Tag, one can switch on a NVE or NE move, preferably choiced, and boost up to triple +6. From there, only a critical hit, or a strong hit at low HP will kill it. Flamethrower and Shadow Ball provide strong, reliable attacks, but Shadow Ball can be replaced with Taunt, which gives you protection against other walls and status, which Chandelure dies to. However, it gives you much less coverage. Note that this set is walled by the likes of Eviolite Chansey in rain, but can OHKO the likes of Kyogre with Shadow Ball while surviving a Scarf full HP Water Spout.
This set is also restricted to the likes of DW Ubers.