Any good even star synchro monsters?

Hey, a strategy I normally do with my deck is use summoner monk and bring out flamvell. This then lets me synchro for eight. I'll also frequently have out a two star monster.... So, any good even star synchros? I run spellcounter, and only 4 synchros (one of them being arcanite magician so he's out). So the only ones i've been bringing out so far are stardust dragon, tempest magician, or thought ruler archfiend. So anyone know good 6, 8, and 10 star synchros I should add? Try to keep them inexpensive, but yeah, if you have like 20 dollar ones on the list i won't mind. Just as long as they're summonable with my cards (spellcaster and non spellcaster tuners, no Odin or such) and useful in a general situation (so no ancient fairy dragon where it's only if my opponent uses field spells),