Use this card in an "Igknight" Deck for both Tribute Summoning it for the effect (and still being able to Pendulum Summon whatever was Tributed) and for a free Special Summon if your Graveyard is set up right.
Even though this card's effect to Special Summon itself appears beneficial, you can always Tribute Summon this card and still activate its effect to Special Summon 1 Normal Monster. However, you can Special Summon this card if you're attempting to Gemini Summon a monster during the same turn.
This works well with Gemini monsters, which count as normal monsters in the graveyard.
You can make some powerful combos with cards like "Gemini Spark" or "Tuned Magician". "Knight of the Red Lotus" will bring back the monster and make the previous card virtually costless.
Tribute a Level 4 Gemini/Normal monster for this card's Tribute Summon, then you can Special Summon the Tributed monster, making this card's Summon cost-effective.
This can be a particularly effective way to re-use "Dark Valkyria"'s normally one-shot effect.
Use "Featherizer" to send Gemini monsters to your Graveyard while also letting you draw cards. Doing so will help you gain hand advantage and send Geminis to the Graveyard, making "Knight of the Red Lotus" easier to summon through its own effect. This combo will also let you Special Summon the monsters you dumped earlier through "Knight of the Red Lotus's" second effect.