Bring back exotic class items, maybe 3 per class, give them unique perks you can choose from in addition to mod slots. Add a baseline increase to ability recharge that is in addition to armor stats. Have them each be part of a quest chain exploring the history of your class/subclasses. There's tons of cool thematic things that can be done and it's balanced by putting effort in. Let me straight up wrap part of an ascendant realm around my arm so I can toss out a nova bomb that stun locks bosses, or part of the infinite forest that allows you to pick up orbs from your own super?