No debuff bypasses resist, unless explicitly noted (such as Ghostborn's DEF down). However, since Maulie A2 doesn't attack, it *does* bypass affinity check.
For Maulie, by far the two most important stats are SPD and ACC. You need her to go before the other team so they can't use their big nuke moves, and you need her to land the provoke. That said, you need to land the provoke mainly against nukers, who don't run very much RES typically.
Aim to have her fast enough to go after your speed booster with no cut-ins. Aim for around 250-300 ACC. After that, focus on DEF and HP. 3200 DEF and 50K HP are good targets.
For Mortu, I wouldn't run Taunting. Yes, you want him to be attacked, but you don't want him to be the focus. Since you're building him to kill, you won't be able to run as much defensive gear. Ideally, you'll get your procs from low-damage AOE effects, like Arbiter A2. Typically he's on a go-second team, so you'll want about 3200 DEF, 60K HP, and 450 RES (less if you have a RES aura). You'll want about 180-200 SPD. All other stats should go into maximizing CRATE and CDMG. You can ignore ATK and ACC.
Alternatively, if you can rely on someone on your team to remove debuffs, you *could* forego the RES, but that's a risky move, since debuffs will bring him down fast.
