Actually, a cleverly-spread base 495 can make him very dangerous. Look at Ononokusu. He doesn't have a BST over 500 and he's a ridiculously dangerous sweeper if played correctly. Scizor has exactly base 500 in stats, but hit top usage in April 2010. Actually, a ton of strong pokes in 5th Gen don't even hit 500 in the stats department, but look where they are.Since Jestaisy has a BST of 495 and was actually made to be really weak outside sun, I'd recommend including BSTs and bumping up the stats. The BST of Jalorda is actually 528, and since everyone doubts it'll get past UU, that's pretty darn high. Torterra's is 525. The Fire-Fighting monkey beast known as Infernape has 534. Anything below 500 for starters is too low I'd say.
EDIT: Lol, didn't know TEA_DEMON meant the prevos. Whoops. In that case, you actually need to bump the stats down. The fully-evolved Water starter has a BST of 572. Either bump the attacking stats down a ton or the defensive stats a ton, or both. Dunno.