You can only control one Laundsallyn
Send one Normal LIGHT monster from your field to the graveyard to special summon this monster from the hand or graveyard.
Once a turn, you can tribute a face up Noble Knight monster to add one Noble Arms from your deck to your hand. This effect can only be activated once a turn.
Although it seems to be a bad card on first thought, it actually is hiding very abusable potential.
That is, that you can send one Normal Light monster from your field to revive himself from the graveyard.
If you can get that Normal Light monster at next to no cost, which normal monsters usually are, it is an easy and free 2k Attacker, or a level 5 for the exceed summon.
Now, what sort of decks have easy access to Light Normal Monsters?
From top tables, Heiratics, Heroes with their Alius.
Branching out from there, Blue Eyes White Dragon decks, Ojama decks, TG Agents.
Although Heroes comes up, usability is a huge issue there.
Giving up a Neos Alius or Sparkman for Ignoble Knight is a huge sacrifice. It ensures your monsters are in the graveyard, but its only a 100/400 jump in power. Not quite enough to merit a sacrifice.
Heiratics might be a go to choice, as lining up level 5s for the exceed is extremely easy with Heiratics, and with Ignoble knight in the mix, you start lining up 4 or 5 level 5s at once with ease.
The two main decks I find Ignoble Knight fits into are Ojamas and Agents.
Lets start with Agents. The obvious sacrifice target is Mystical Shine Ball.
With plays like Venus -> 3 Shine Balls -> Sacrifice one for Ignoble Knight, make a Gachi Gachi Gantetsu, letting ignoble knight turns your previously useless sacrificial lambs into something of a threat.
But, agents only have sort of an one shot at this +3 advantage combo. What about something more stable in being able to generate empty advantage to turn into Ignoble Knight.
Of course, we are talking about Ojamas.
Everyone is already familiar with the rampant advantage Ojamas create. Its +2s, +3s, or even +4s left right and center.
The main problem is that their advantage... never really did anything.
And now, with exceeds and Ignoble Knight, they have full access to an arsenal of powerhouses for next to no cost.
Another thing Ojamas can do is Junk synchron plays.
Summon a Junk Synchron and revive an Ojama. Send that Ojama to the graveyard to revive Ignoble Knight, and Synchro for a Junk Destroyer, ripping open one card on the opponents field.
Not to mention plays with Debris Dragon as well.
Summon a Debris Dragon, and revive an Ojama in ATK position. Plop down an Ojama Country and make them 2000 and 1000 attack respectively. Discard Ignoble knight to revive an Ojama, swing for 4k, and main phase 2 create a Ignoble Knight and Iron Chain Dragon for the even higher power on the defense.
Whether or not igNOBLE knight can tribute itself for the search is yet to be confirmed.