Iconoclast Rampagers give a mild shit, as they can't fall back 1" and re-charge a unit for +1A if combat drags out more than one turn. These lords that pilot Knight Desecrators find expression in a desire to relentlessly annihilate every trace of their enemies. Infernal: If you're rocking the conflagration cannon and thundercoil harpoon, any Daemonic Surge effect will be beneficial. You decide. The FAQ clarified that the exploding dice mechanic also works on the relic melee weapons, making Rampagers ideal for carrying the Gauntlet of Ascension or the Teeth that Hunger. Notably, if you take the Knower of Profane Secrets Pact, the Forsaken Damnation, and this relic, your Damnations will only trigger on 12s normally - i.e. The Lancer is a dedicated anti-knight melee unit that excels when it can go toe-to-toe with other titanics. The Volkite Chierovile is basically a RFBC with one better AP, 5 shots instead of 2d6, shorter range, and d6 damage instead of d3. The Iconoclast ambition also makes the unit slightly better in close combat, although with the amount of guns a Tyrant has, you stand a chance of making its points back even if you only shoot and never charge. A Chaos Knight can Fall Back in the Movement phase and still shoot and/or charge during its turn. Combine this with the Helm of Warp-Sight on a ranged Knight and stop caring - you were never going to charge or advance anyway, and now you ignore hit roll penalties. It makes two hit rolls for each attack instead of one. Useful when it comes up, but remember, you usually can't shoot characters, and very few targets will ever be Titanic.
Do not underestimate this power. Knight Armigers for the loyalist knights are surprisingly versatile and resilient units, able to fulfil the role of infantry/monster melee hunters or bullet hoses as needed. The iconoclast trait solves (most) of these. Since all models were FAQ'd to have a "Close Combat Weapon" (Strength: User/AP: 0/Damage: 1) this ambition applies here as well. The Lightning Cannon is an odd weapon. Additionally, you get the VEHICLE and CHAOS KNIGHTS keywords, and all but the Armigers get TITANIC. There's an argument for every kind of weapon, but the absolute best is a pair of Avenger Gatling Cannons as stated above. The shootiest, tankiest of the Renegade Knights (Reduced BS 2+ to 3+, T 9 to 8, and Armor save from 2+ to 3+ with no point decrease with the new "SUPER FORGEWORLD KNIGHTS UPDATE" has basically gimped an already overcosted model to the point of being a glorified target vs taking 2 rapid fire battle cannon despoilers for an average of 24 strength 8 ap -2 damage d3 shots, 2 targets, and 18 more total wounds).
It's Assault, firstly, you'll be in or near melee range most of the time with it, and D3+1 Melta shots sounds a lot more reliable than just D3. This may have some value on a Knight equipped with the Helm of Warp-Sight, as it would allow you to fire the Icarus Autocannons at native BS regardless of target.
Doubling down with both Corrupted Heirlooms and Tyrannical Court might not be a bad idea in a mostly Tyrant-class knight army. Getting a 4++ against close combat attacks is pretty slick [also-1 to be hit by titanic units], though. 24 wounds and a 5++ invuln against shooting, so it isn't leaving the tabletop any time soon, but a fully kitted-out (with huge gun and carapace weapon) one costs even more than a (cheap) Lord of Skulls and doesn't regenerate. Since you may be bringing along a Disloyal 32, swap out a Renegade Commander for a Malefic Lord with Creeping Terror, and that's an additional -d3 to the leadership of the effected unit. Note that this doesn't have the rules to to throw. However, some of their main weaknesses were low attack counts, an inability to retreat from combat and continue fighting, and poor ap on their sweeping chainswords. You'd like to run a Passable Superheavy-Unit only list for Chaos and don't want to go to Forgeworld We talked a lot about letting your knights taking more wounds above... but come on, having your knight get bruised and scratched to get buffed or summon daemons is one thing, but letting your opponent do more damage to on purpose with no benefit is inexcusable. You can't take any number of them aside from 2 or 4 on the models that can have them, but don't take more than 4 army wide, even if you've paid for two of the carriers. Like rhinos.
If you don't take the claw, you are clocking in at nearly the same price as an atropos or a Double Battle Cannon Despoiler. Note that since you only have 1 datasheet, you're limited to 3 units total of these, unlike loyalists, who can take 3 of each loadout (and for everybody, each unit can have up to 3 members). Paired with Infernal and the Full Tilt stratagem, that's M16, Advance 1d6+1, Charge 2d6+1 - on average, you can get into melee with something 30 inches away (easily inside enemy deployment turn 1)! They do not get Traits dedicated to specific houses like the Imperials.