Feldon of the Third Path
Feldon is great reanimator commander in mono red, and often included in the 99 as an engine piece or haste enabler in other decks with red. Feldon allows for multiple copies of a single creature, as the ability leaves the original card in the graveyard, which is rare in reanimating effects.
Themes for Feldon of the Third Path
Red Artifacts
Red has great synergies with artifacts, and mono red artifact decks always run lots of artifacts as permanent ramp, and often as ways to get card draw. Red artifact decks are a combination of tutoring, sacrifice effects, artifact ETBs and reanimation to get the upper hand.
Burn
Burn is reds primary mechanics. Red can deal massive amounts of damage to single target or deal multiple amounts of single damage to multiple targets. Burn decks aim to win with massive outbursts of big, uncounterable and unpreventable damage to opponents (and sometimes the burn player itself).
Dragon tribal
Dragons, alongside Goblins, are reds primary creature types. Dragons are reds strongest creatures and most of the expansions have some kind of red dragon in them. As dragons are expensive to cast, dragon tribal decks run multiple cost reduction effects and have ways to cheat the expensive dragons on the battlefield.