Slice off tops of garlic. Place in foil; drizzle with olive oil, salt, and pepper. Close foil loosely and place on grill.
Remove most of husk from corn leaving only the thin pale green husk layer. Peel back husk removing silk; replace husk. Roast corn turning as needed (about every 2 minutes) until corn is golden brown, approximately 10 minutes. Remove from grill.
Stack tortillas in foil; sprinkle with a little water from fingertips. Close foil and place on grill to warm.
Whisk together in medium bowl olive oil, lime juice, orange juice, sea salt, pepper, and chile powder.
While corn is still warm shuck and remove from cob. Mix with olive oil/lime juice mixture. Add red pepper, onion, and cilantro.
Check the garlic - it's done when yields to soft pressure and is nicely browned. Squeeze out roasted garlic and spread on warmed tortilla. Fill tortilla with corn mixture. Add slices of avocado and garnish with tomatoes.