Hoopa-U's purpose in this core is to KO Clefable with Gunk Shot and Ferrothorn with Fire Punch, as they both prevent Manaphy from sweeping. It also pressures Zard X from coming in and threatens to KO Jellicent with Hyperspace Fury. As those three moves basically covered what it needed to, I added Grass Knot, as even with a hindering nature it still 2HKO's Hippo. Adamant because it still won't outspeed Zard X with Jolly and wants more power.
Manaphy sweeps this team once Clef and Ferro are gone, being able to blow through Hippo, Jelli, and Mandibuzz after a boost. The coverage moves are chosen to beat them. Scald is used over Surf to wear down Clef more easily. Ice Beam in particular is very important, as it's one of this core's main ways of beating Mandibuzz, which otherwise checks Hoopa-U. Life orb guarantees the 2HKO without a boost. The speed Evs outrun Zard X by one point, while allowing for a little bulk in HP.
Lando-T is very useful for this core because it checks Zard X, which can set up a DD and win if
allowed to. It pressures Mandibuzz, a big threat, with Stone Edge, and can explode when it's weakened. Most importantly, Lando-T can get Hoopa-U and Manaphy inside safely with its U-Turns.