Red-Eyes B. Dragon and Red-Eyes Zombie Dragon are the main target of Red-Eyes Spirit when they are sent to the Graveyard. These cards have decent stats which gives you a solid offense and defense capabilities.
Cards of the Red Stone can be used when you have a Level 7 Red-Eyes monster in your hand, send the Red-Eyes monster from your hand to the Graveyard then draw 2 cards, you can then send another Level 7 Red-Eyes monster from your deck to the Graveyard.
By sending Red-Eyes monster (Except Red-Eyes B. Chick) from your Hand or Deck, Red-Eyes Insight lets you get Red-Eyes Spell/Trap from your Deck then add it to your Hand.
Red-Eyes Wyvern is a 1800 beater that has a great effect. If you didn't summon or set a monster in a turn, you can banish this card from your Graveyard during the End Phase to Special Summon a Red-Eyes monster from your Graveyard.
Meteor Dragon Red-Eyes Impact is a Red-Eyes support that can protect your other Red-Eyes monster from getting destroyed by battle or card effects. The ability is quite useful, but since it's a Gemini monster, it needs to be summoned again after it's summoned to have the ability available, making it much harder and slower to achieve.
Most Fusion monsters must be summoned properly first before they can be revived from the Graveyard. That's part of the basic rule for Fusion monsters :)
The only exception is Fusion monsters that states they cannot be Special Summoned in any way except by a Fusion Summon. In that case, even if you Fusion Summoned them properly, you still cannot revive them.