ReachReach is a static ability.
A creature with flying can’t be blocked except by creatures with flying and/or reach. (See rule 509, “Declare Blockers Step,” and rule 702.9, “Flying.”)
Multiple instances of reach on the same creature are redundant. (CR 702.17)
Whenever one or more land cards are put into your graveyard from anywhere, you gain 2 life.
At the beginning of your upkeep, if there are four or more land cards in your graveyard and you both own and control Titania, Voice of Gaea and a land named Argoth, Sanctum of Nature,
exileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) them, then
meldMeld is a keyword action that appears in an ability on one card in a meld pair. To meld the two cards in a meld pair, put them onto the battlefield with their back faces up and combined. The resulting permanent is a single object represented by two cards. See rule 712, “Double-Faced Cards.”
Only two cards belonging to the same meld pair can be melded. Tokens, cards that aren’t meld cards, or meld cards that don’t form a meld pair can’t be melded.
If an effect instructs a player to meld objects that can’t be melded, they stay in their current zone. (CR 701.42) them into Titania, Gaea Incarnate.