A semi-joke retrain of my favorite fusion monster along with a counterpart. I've made no attempt to balance either of these but tried to make them somewhat realistic and at least usable in a casual game.
Sanwitch of Forbidden Arts
Spellcaster/Fusion/DARK/Lv6/ATK2100/DEF1800
"1 Level 3 Fiend monster + 1 Level 4 Spellcaster monster
The first time each turn a monster you control is sent from the field to the GY; add one monster from your deck to your hand with ATK less than or equal to that sent monster, then this card gains ATK equal to the ATK of the added monster, you can only activate this effect of "Sanwitch of The Forbidden Arts" once per turn. If this card would be removed from the field you can banish one "Sangan" or "Witch of the Black Forest" from your GY instead"
Goddess of The Chestnut Grove
Fairy/Fusion/LIGHT/Lv4/ATK1500/DEF1200
""Kuriboh" + "Goddess with the Third Eye"
Once per turn, when a monster you control is targeted for an attack, you can reveal one Fusion Monster from your Extra Deck that lists that targeted monster; tribute that monster and discard monsters from your hand equal to the number of other listed Fusion Materials, then Special Summon that revealed Fusion Monster (this is treated as a Fusion Summon) and it becomes the attack target instead. This card cannot be targeted for attacks or your opponent's card effects while you control another Fusion Monster."